Hyper-Leonardo numbers

DefinitionHyper-Leonardo numbers#✓fully proved

Let \(Le_n\) be the Leonardo numbers, defined by \(Le_0 = Le_1 = 1\) and \(Le_{n+2} = Le_{n+1} + Le_n + 1\). The hyper-Leonardo numbers are the integers \(Le^{(r)}_n\), for \(r, n \ge 0\), defined by \(Le^{(0)}_n = Le_n\) and \(Le^{(r+1)}_n = \sum_{k=0}^{n} Le^{(r)}_k\).

def hyperLeonardo : ℕ → ℕ → ℤ
  | 0, n => genLeonardo 1 n
  | r + 1, n => ∑ k ∈ Finset.range (n + 1), hyperLeonardo r k
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Definition 1, as displayed in the derivation Le^{(1)}_n = ∑_{k=0}^{n} Le^{(0)}_k after Proposition 5.
Uses 1 · Used by 15

TheoremHyper-Leonardo numbers of order zero#✓fully proved

For every natural number \(n\), the hyper-Leonardo number \(Le^{(0)}_n\) equals the Leonardo number \(L_{1,n}\), the generalized Leonardo number with \(k = 1\), given by \(L_{1,0} = L_{1,1} = 1\) and \(L_{1,n+2} = L_{1,n+1} + L_{1,n} + 1\).

theorem hyperLeonardo_zero (n : ℕ) : hyperLeonardo 0 n = genLeonardo 1 n
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, Definition 1.
Uses 2

TheoremHyper-Leonardo numbers as partial sums#✓fully proved

For all natural numbers \(r\) and \(n\), the hyper-Leonardo numbers \(Le^{(r)}_n\) satisfy \(Le^{(r+1)}_n = \sum_{k=0}^{n} Le^{(r)}_k\).

theorem hyperLeonardo_succ (r n : ℕ) :
    hyperLeonardo (r + 1) n = ∑ k ∈ Finset.range (n + 1), hyperLeonardo r k
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, Definition 1.
Uses 1

TheoremFirst hyper-Leonardo numbers of order one#✓fully proved

The hyper-Leonardo numbers \(Le^{(1)}_n\) of order \(1\) satisfy \(Le^{(1)}_0 = 1\), \(Le^{(1)}_1 = 2\), \(Le^{(1)}_2 = 5\) and \(Le^{(1)}_3 = 10\).

theorem hyperLeonardo_one_small :
    hyperLeonardo 1 0 = 1 ∧ hyperLeonardo 1 1 = 2 ∧ hyperLeonardo 1 2 = 5 ∧
      hyperLeonardo 1 3 = 10
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, Proposition 1 (Le^{(1)}_0 = 1, Le^{(1)}_1 = 2).
Uses 2

DefinitionHyper-Fibonacci numbers#✓fully proved

The hyper-Fibonacci numbers \(F^{(r)}_n\), for natural numbers \(r\) and \(n\), are the natural numbers defined by \(F^{(0)}_n = F_n\), the \(n\)-th Fibonacci number (with \(F_0 = 0\) and \(F_1 = 1\)), and \(F^{(r+1)}_n = \sum_{k=0}^{n} F^{(r)}_k\).

def hyperFibonacci : ℕ → ℕ → ℕ
  | 0, n => Nat.fib n
  | r + 1, n => ∑ k ∈ Finset.range (n + 1), hyperFibonacci r k
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, the hyper-Fibonacci numbers F^{(r)}_{n+1} = ∑_{k=0}^{n+1} F^{(r-1)}_k displayed after Proposition 5.
Used by 7

TheoremHyper-Fibonacci numbers of order zero#✓fully proved

For every natural number \(n\), the hyper-Fibonacci number \(F^{(0)}_n\) equals the \(n\)-th Fibonacci number \(F_n\) (with \(F_0 = 0\) and \(F_1 = 1\)).

theorem hyperFibonacci_zero (n : ℕ) : hyperFibonacci 0 n = Nat.fib n
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, after Proposition 5.
Uses 1

TheoremHyper-Fibonacci numbers as partial sums#✓fully proved

For all natural numbers \(r\) and \(n\), the hyper-Fibonacci numbers \(F^{(r)}_n\) satisfy \(F^{(r+1)}_n = \sum_{k=0}^{n} F^{(r)}_k\).

theorem hyperFibonacci_succ (r n : ℕ) :
    hyperFibonacci (r + 1) n = ∑ k ∈ Finset.range (n + 1), hyperFibonacci r k
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, after Proposition 5.
Uses 1

TheoremSmall values of the hyper-Fibonacci numbers of order one#✓fully proved

The hyper-Fibonacci numbers \(F^{(1)}_n\) of order \(1\) satisfy \(F^{(1)}_0 = 0\), \(F^{(1)}_1 = 1\), \(F^{(1)}_2 = 2\) and \(F^{(1)}_3 = 4\).

theorem hyperFibonacci_one_small :
    hyperFibonacci 1 0 = 0 ∧ hyperFibonacci 1 1 = 1 ∧ hyperFibonacci 1 2 = 2 ∧
      hyperFibonacci 1 3 = 4
Sources
  • Spreafico and Catarino, INTEGERS 26 (2026), Article A48, after Proposition 5 (F^{(r)}_0 = 0).
Uses 1

TheoremRecurrences for the hyper-Leonardo numbers of orders zero, one and two#●ready to prove

The hyper-Leonardo numbers \(Le^{(r)}_n\) satisfy \(Le^{(0)}_0 = Le^{(0)}_1 = 1\), \(Le^{(1)}_0 = 1\), \(Le^{(1)}_1 = 2\), \(Le^{(2)}_0 = 1\) and \(Le^{(2)}_1 = 3\), and for every natural number \(n \ge 2\),

\[Le^{(0)}_n = Le^{(0)}_{n-1} + Le^{(0)}_{n-2} + 1,\]
\[Le^{(1)}_n = Le^{(1)}_{n-1} + Le^{(1)}_{n-2} + \binom{n-1}{1} + 1,\]
\[Le^{(2)}_n = Le^{(2)}_{n-1} + Le^{(2)}_{n-2} + \binom{n}{2} + \binom{n-1}{1} + 2.\]
public theorem_wanted hyperLeonardo_recurrence_small_order :
    (∀ n, hyperLeonardo 0 (n + 2) = hyperLeonardo 0 (n + 1) + hyperLeonardo 0 n + 1) ∧
    hyperLeonardo 0 0 = 1 ∧ hyperLeonardo 0 1 = 1 ∧
    (∀ n, hyperLeonardo 1 (n + 2) =
      hyperLeonardo 1 (n + 1) + hyperLeonardo 1 n + ((n + 1).choose 1 : ℕ) + 1) ∧
    hyperLeonardo 1 0 = 1 ∧ hyperLeonardo 1 1 = 2 ∧
    (∀ n, hyperLeonardo 2 (n + 2) = hyperLeonardo 2 (n + 1) + hyperLeonardo 2 n +
      ((n + 2).choose 2 : ℕ) + ((n + 1).choose 1 : ℕ) + 2) ∧
    hyperLeonardo 2 0 = 1 ∧ hyperLeonardo 2 1 = 3
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 1.
Uses 1

TheoremRecurrence for the hyper-Leonardo numbers#●ready to prove

For every natural number \(r\), the hyper-Leonardo numbers \(Le^{(r)}_n\) of order \(r\) satisfy \(Le^{(r)}_0 = 1\), \(Le^{(r)}_1 = r + 1\) and, for every natural number \(n \ge 2\), \(Le^{(r)}_n = r + Le^{(r)}_{n-1} + Le^{(r)}_{n-2} + \binom{n+r-2}{r} + \sum_{j=1}^{r-1} j \binom{n+r-2-j}{r-j}\).

public theorem_wanted hyperLeonardo_recurrence (r : ℕ) :
    (∀ n, hyperLeonardo r (n + 2) = r + hyperLeonardo r (n + 1) + hyperLeonardo r n +
      ((n + r).choose r : ℕ) +
        ∑ j ∈ Finset.Ico 1 r, (j * (n + r - j).choose (r - j) : ℕ)) ∧
    hyperLeonardo r 0 = 1 ∧ hyperLeonardo r 1 = r + 1
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 2.
Uses 1

TheoremRecurrence across consecutive orders of hyper-Leonardo numbers#●ready to prove

For all natural numbers \(r \ge 1\) and \(n \ge 1\), the hyper-Leonardo numbers \(Le^{(r)}_n\) satisfy \(Le^{(r)}_n = Le^{(r)}_{n-1} + Le^{(r-1)}_n\).

public theorem_wanted hyperLeonardo_succ_succ (r n : ℕ) :
    hyperLeonardo (r + 1) (n + 1) = hyperLeonardo (r + 1) n + hyperLeonardo r (n + 1)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 3, Equation (4).
Uses 1

TheoremConsecutive hyper-Leonardo numbers of order one#●ready to prove

For every natural number \(n\), the hyper-Leonardo numbers \(Le^{(1)}_n\) of order \(1\) satisfy \(Le^{(1)}_{n+1} = Le^{(1)}_n + L_{1,n+1}\), where \(L_{1,n}\) is the generalized Leonardo number with \(k = 1\), that is, the Leonardo number \(Le_n\).

This is the case \(r = 1\) of the recurrence \(Le^{(r)}_n = Le^{(r)}_{n-1} + Le^{(r-1)}_n\). The extracted text of the source reads \(Le^{(1)}_n = Le_{n-1} + Le_n\), which fails at \(n = 2\), where \(Le^{(1)}_2 = 5\) but \(Le_1 + Le_2 = 4\).

public theorem_wanted hyperLeonardo_one_succ (n : ℕ) :
    hyperLeonardo 1 (n + 1) = hyperLeonardo 1 n + genLeonardo 1 (n + 1)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Corollary 1, Equation (5).
Uses 2

TheoremGenerating function of shifted binomial coefficients#✓fully proved

For every natural number \(r\), the formal power series \(\sum_{n \ge 0} \binom{n+r}{r} t^n\) with integer coefficients satisfies \(\left(\sum_{n \ge 0} \binom{n+r}{r} t^n\right)(1-t)^{r+1} = 1\) in \(\mathbb{Z}[[t]]\), that is, \(\sum_{n \ge 0} \binom{n+r}{r} t^n = 1/(1-t)^{r+1}\).

The paper states this for positive \(r\); it holds for every \(r \ge 0\) and is stated so.

public theorem choose_add_powerSeries_mul_one_sub_pow (r : ℕ) :
    PowerSeries.mk (fun n => (((n + r).choose r : ℕ) : ℤ)) * (1 - X) ^ (r + 1) = 1
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Lemma 2.

TheoremThe convolution of log-concave sequences is log-concave#●ready to prove

Let \((x_n)_{n \ge 0}\) and \((y_n)_{n \ge 0}\) be sequences of positive real numbers that are log-concave, that is, \(x_{j-1} x_{j+1} \le x_j^2\) and \(y_{j-1} y_{j+1} \le y_j^2\) for every \(j \ge 1\). Let \(z_n = \sum_{k=0}^{n} x_k y_{n-k}\) be their convolution. Then \(z_{j-1} z_{j+1} \le z_j^2\) for every \(j \ge 1\).

Positivity is the paper's standing assumption on log-concave sequences.

public theorem_wanted logConcave_convolution (x y : ℕ → ℝ) (hx : ∀ n, 0 < x n)
    (hy : ∀ n, 0 < y n) (hxlc : ∀ j, 1 ≤ j → x (j - 1) * x (j + 1) ≤ x j ^ 2)
    (hylc : ∀ j, 1 ≤ j → y (j - 1) * y (j + 1) ≤ y j ^ 2) (j : ℕ) (hj : 1 ≤ j) :
    (∑ k ∈ Finset.range j, x k * y (j - 1 - k)) *
        (∑ k ∈ Finset.range (j + 2), x k * y (j + 1 - k)) ≤
      (∑ k ∈ Finset.range (j + 1), x k * y (j - k)) ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Lemma 3, quoting [1].

TheoremGenerating function of the Leonardo numbers#●ready to prove

Let \(Le_n\) be the Leonardo numbers (\(Le_0 = Le_1 = 1\) and \(Le_{n+2} = Le_{n+1} + Le_n + 1\)), and let \(L(t) = \sum_{n \ge 0} Le_n t^n\) in the ring \(\mathbb{Z}[[t]]\) of formal power series. Then \(L(t)(1 - 2t + t^3) = 1 - t + t^2\) and \(L(t)(1 - t - t^2)(1 - t) = 2(1 - t) - (1 - t - t^2)\).

Equivalently, \(L(t) = \frac{2}{1-t-t^2} - \frac{1}{1-t} = \frac{1-t+t^2}{1-2t+t^3}\); the identities above are this equality with the denominators cleared.

public theorem_wanted leonardo_generatingFunction :
    PowerSeries.mk (fun n => genLeonardo 1 n) * (1 - 2 * X + X ^ 3) = 1 - X + X ^ 2 ∧
      PowerSeries.mk (fun n => genLeonardo 1 n) * ((1 - X - X ^ 2) * (1 - X)) =
        2 * (1 - X) - (1 - X - X ^ 2)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Corollary 2.
Uses 1

TheoremGenerating functions of the hyper-Leonardo numbers of orders one and two#●ready to prove

In the ring \(\mathbb{Z}[[t]]\) of formal power series, the hyper-Leonardo numbers \(Le^{(r)}_n\) satisfy \(\left(\sum_{n \ge 0} Le^{(1)}_n t^n\right)(1 - 2t + t^3)(1 - t) = 1 - t + t^2\) and \(\left(\sum_{n \ge 0} Le^{(2)}_n t^n\right)(1 - 2t + t^3)(1 - t)^2 = 1 - t + t^2\).

Equivalently, the two generating functions are \(\frac{1 - t + t^2}{(1 - 2t + t^3)(1 - t)}\) and \(\frac{1 - t + t^2}{(1 - 2t + t^3)(1 - t)^2}\).

public theorem_wanted hyperLeonardo_one_two_generatingFunction :
    PowerSeries.mk (fun n => hyperLeonardo 1 n) * ((1 - 2 * X + X ^ 3) * (1 - X)) =
        1 - X + X ^ 2 ∧
      PowerSeries.mk (fun n => hyperLeonardo 2 n) * ((1 - 2 * X + X ^ 3) * (1 - X) ^ 2) =
        1 - X + X ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Corollary 3.
Uses 1

TheoremGenerating function of the hyper-Leonardo numbers#●ready to prove

For every natural number \(r\), the formal power series \(\sum_{n \ge 0} \mathrm{Le}^{(r)}_n t^n\) of the hyper-Leonardo numbers of order \(r\) satisfies \(\left(\sum_{n \ge 0} \mathrm{Le}^{(r)}_n t^n\right)(1-2t+t^3)(1-t)^r = 1-t+t^2\) in \(\mathbb{Z}[[t]]\), that is, \(\sum_{n \ge 0} \mathrm{Le}^{(r)}_n t^n = \frac{1-t+t^2}{(1-2t+t^3)(1-t)^r}\).

public theorem_wanted hyperLeonardo_generatingFunction (r : ℕ) :
    PowerSeries.mk (fun n => hyperLeonardo r n) * ((1 - 2 * X + X ^ 3) * (1 - X) ^ r) =
      1 - X + X ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Theorem 1, Equation (10).
Uses 1

TheoremHyper-Leonardo numbers in terms of hyper-Fibonacci numbers#●ready to prove

For all natural numbers \(r\) and \(n\), the hyper-Leonardo number \(\mathrm{Le}^{(r)}_n\) and the hyper-Fibonacci number \(F^{(r)}_{n+1}\) satisfy \(\mathrm{Le}^{(r)}_n = 2F^{(r)}_{n+1} - \binom{n+r}{r}\) as integers.

public theorem_wanted hyperLeonardo_eq_hyperFibonacci (r n : ℕ) :
    hyperLeonardo r n = 2 * (hyperFibonacci r (n + 1) : ℤ) - ((n + r).choose r : ℕ)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 6, Equation (9).
Uses 2

TheoremLog-convexity and log-concavity of the Leonardo numbers#●ready to prove

Let \(Le_n\) be the Leonardo numbers (\(Le_0 = Le_1 = 1\) and \(Le_{n+2} = Le_{n+1} + Le_n + 1\)). Then \(Le_n^2 \le Le_{n-1} Le_{n+1}\) for \(n = 1\) and \(n = 3\), \(Le_5^2 = Le_4 Le_6\), and \(Le_{n-1} Le_{n+1} \le Le_n^2\) for \(n = 2\), \(n = 4\) and every \(n \ge 6\).

The paper's "the sequence is log-convex for \(n = 1\)" is read as the defining inequality at index \(n\).

public theorem_wanted leonardo_logConvex_logConcave_pointwise :
    (∀ n ∈ ({1, 3} : Finset ℕ),
      genLeonardo 1 n ^ 2 ≤ genLeonardo 1 (n - 1) * genLeonardo 1 (n + 1)) ∧
    genLeonardo 1 5 ^ 2 = genLeonardo 1 4 * genLeonardo 1 6 ∧
    (∀ n, n = 2 ∨ n = 4 ∨ 6 ≤ n →
      genLeonardo 1 (n - 1) * genLeonardo 1 (n + 1) ≤ genLeonardo 1 n ^ 2)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 10.
Uses 1

TheoremLeonardo numbers are log-balanced at index three#●ready to prove

Let \(Le_n\) be the Leonardo numbers (\(Le_0 = Le_1 = 1\) and \(Le_{n+2} = Le_{n+1} + Le_n + 1\)). Then \(Le_3^2 \le Le_2 Le_4\) and \(\frac{Le_2}{2!} \cdot \frac{Le_4}{4!} \le \left(\frac{Le_3}{3!}\right)^2\), the second inequality in the real numbers. That is, \((Le_n)\) satisfies the log-convexity inequality at \(n = 3\) and \((Le_n / n!)\) satisfies the log-concavity inequality at \(n = 3\).

public theorem_wanted leonardo_logBalanced_three :
    genLeonardo 1 3 ^ 2 ≤ genLeonardo 1 2 * genLeonardo 1 4 ∧
      ((genLeonardo 1 2 : ℝ) / Nat.factorial 2) * ((genLeonardo 1 4 : ℝ) / Nat.factorial 4) ≤
        ((genLeonardo 1 3 : ℝ) / Nat.factorial 3) ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 11, with the definition of log-balanced displayed before Proposition 10.
Uses 1

TheoremLog-convexity and log-concavity of the hyper-Leonardo numbers at index one#●ready to prove

The hyper-Leonardo numbers \(\mathrm{Le}^{(r)}_n\) satisfy \(\left(\mathrm{Le}^{(1)}_1\right)^2 \le \mathrm{Le}^{(1)}_0 \mathrm{Le}^{(1)}_2\), and for every natural number \(r \ge 2\) they satisfy \(\mathrm{Le}^{(r)}_0 \mathrm{Le}^{(r)}_2 \le \left(\mathrm{Le}^{(r)}_1\right)^2\).

public theorem_wanted hyperLeonardo_logConvex_logConcave_one :
    hyperLeonardo 1 1 ^ 2 ≤ hyperLeonardo 1 0 * hyperLeonardo 1 2 ∧
      ∀ r, 2 ≤ r → hyperLeonardo r 0 * hyperLeonardo r 2 ≤ hyperLeonardo r 1 ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 12.
Uses 1

TheoremEventual log-concavity of the hyper-Leonardo numbers of order one#●ready to prove

For every natural number \(n \ge 2\), the hyper-Leonardo numbers \(Le^{(1)}_n\) of order \(1\) satisfy \(Le^{(1)}_{n-1} Le^{(1)}_{n+1} \le (Le^{(1)}_n)^2\).

public theorem_wanted hyperLeonardo_one_logConcave (n : ℕ) (hn : 2 ≤ n) :
    hyperLeonardo 1 (n - 1) * hyperLeonardo 1 (n + 1) ≤ hyperLeonardo 1 n ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 13.
Uses 1

TheoremCassini-type identity for hyper-Leonardo numbers#●ready to prove

For all natural numbers \(r \ge 1\) and \(n \ge 1\), the hyper-Leonardo numbers \(Le^{(r)}_n\) satisfy \(Le^{(r)}_{n-1} Le^{(r)}_{n+1} - (Le^{(r)}_n)^2 = Le^{(r)}_n Le^{(r-1)}_{n+1} - Le^{(r-1)}_n Le^{(r)}_{n+1}\).

public theorem_wanted hyperLeonardo_mul_sub_sq (r n : ℕ) :
    hyperLeonardo (r + 1) n * hyperLeonardo (r + 1) (n + 2) - hyperLeonardo (r + 1) (n + 1) ^ 2 =
      hyperLeonardo (r + 1) (n + 1) * hyperLeonardo r (n + 2) -
        hyperLeonardo r (n + 1) * hyperLeonardo (r + 1) (n + 2)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 4.
Uses 1

TheoremEventual log-concavity of the hyper-Leonardo numbers of positive order#●ready to prove

For all natural numbers \(r \ge 1\) and \(n \ge 2\), the hyper-Leonardo numbers \(Le^{(r)}_n\) of order \(r\) satisfy \(Le^{(r)}_{n-1} Le^{(r)}_{n+1} \le (Le^{(r)}_n)^2\).

The source states this for \(r \ge 0\), but it fails for the Leonardo numbers \(Le_n = Le^{(0)}_n\) at \(n = 3\), where \(Le_2 Le_4 = 27 > 25 = Le_3^2\); the source's proof starts its induction at \(r = 1\) (Proposition 13).

public theorem_wanted hyperLeonardo_logConcave {r : ℕ} (hr : 1 ≤ r) {n : ℕ} (hn : 2 ≤ n) :
    hyperLeonardo r (n - 1) * hyperLeonardo r (n + 1) ≤ hyperLeonardo r n ^ 2
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Proposition 14.
Uses 1

TheoremConvexity of the hyper-Leonardo numbers#●ready to prove

For all natural numbers \(r\) and \(n \ge 1\), the hyper-Leonardo numbers \(\mathrm{Le}^{(r)}_n\) satisfy \(2 \mathrm{Le}^{(r)}_n \le \mathrm{Le}^{(r)}_{n-1} + \mathrm{Le}^{(r)}_{n+1}\).

public theorem_wanted hyperLeonardo_convex (r n : ℕ) (hn : 1 ≤ n) :
    2 * hyperLeonardo r n ≤ hyperLeonardo r (n - 1) + hyperLeonardo r (n + 1)
Sources
  • Elen Viviani Pereira Spreafico and Paula Maria Machado Cruz Catarino, A Note on Hyper-Leonardo Numbers, INTEGERS 26 (2026), Article A48, Theorem 3, with the definition of convexity displayed before it.
Uses 1
9 fully proved16 ready to prove

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