A367211 Triangular array read by rows: T(n, k) = binomial(n, k) * A000129(n - k) for 0 <= k < n.
1, 2, 2, 5, 6, 3, 12, 20, 12, 4, 29, 60, 50, 20, 5, 70, 174, 180, 100, 30, 6, 169, 490, 609, 420, 175, 42, 7, 408, 1352, 1960, 1624, 840, 280, 56, 8, 985, 3672, 6084, 5880, 3654, 1512, 420, 72, 9, 2378, 9850, 18360, 20280, 14700, 7308, 2520, 600, 90, 10
Offset: 1
Examples
First nine rows: [n\k] 0 1 2 3 4 5 6 7 8 [1] 1; [2] 2 2; [3] 5 6 3; [4] 12 20 12 4; [5] 29 60 50 20 5; [6] 70 174 180 100 30 6; [7] 169 490 609 420 175 42 7; [8] 408 1352 1960 1624 840 280 56 8; [9] 985 3672 6084 5880 3654 1512 420 72 9; . Row 4 represents the polynomial p(4,x) = 12 + 20 x + 12 x^2 + 4 x^3, so that (T(4,k)) = (12, 20, 12, 4), k = 0..3.
Links
- Rigoberto Flórez, Robinson Higuita, and Antara Mukherjee, Characterization of the strong divisibility property for generalized Fibonacci polynomials, Integers, 18 (2018), Paper No. A14.
Crossrefs
Programs
-
Maple
P := proc(n) option remember; ifelse(n <= 1, n, 2*P(n - 1) + P(n - 2)) end: T := (n, k) -> P(n - k) * binomial(n, k): for n from 1 to 9 do [n], seq(T(n, k), k = 0..n-1) od; # (after Werner Schulte) Peter Luschny, Nov 24 2023
-
Mathematica
p[1, x_] := 1; p[2, x_] := 2 + 2 x; u[x_] := p[2, x]; v[x_] := 1 - 2 x - x^2; p[n_, x_] := Expand[u[x]*p[n - 1, x] + v[x]*p[n - 2, x]] Grid[Table[CoefficientList[p[n, x], x], {n, 1, 10}]] Flatten[Table[CoefficientList[p[n, x], x], {n, 1, 10}]] (* Or: *) T[n_, k_] := Module[{P}, P[m_] := P[m] = If[m <= 1, m, 2*P[m - 1] + P[m - 2]]; P[n - k] * Binomial[n, k] ]; Table[T[n, k], {n, 1, 9}, {k, 0, n - 1}] (* Peter Luschny, Mar 07 2025 *)
Formula
p(n, x) = u*p(n-1, x) + v*p(n-2, x) for n >= 3, where p(1, x) = 1, p(2, x) = 2 + 2*x, u = p(2, x), and v = 1 - 2*x - x^2.
p(n, x) = k*(b^n - c^n), where k = sqrt(1/8), b = x + 1 - sqrt(2), c = x + 1 + sqrt(2).
From Werner Schulte, Nov 24 2023 and Nov 25 2023: (Start)
The row polynomials p(n, x) = Sum_{k=0..n-1} T(n, k) * x^k satisfy the equation p'(n, x) = n * p(n-1, x) where p' is the first derivative of p.
T(n, k) = T(n-1, k-1) * n / k for 0 < k < n and T(n, 0) = A000129(n) for n > 0.
T(n, k) = A000129(n-k) * binomial(n, k) for 0 <= k < n.
G.f.: t / (1 - (2+2*x) * t - (1-2*x-x^2) * t^2). (End)
Extensions
New name using a formula of Werner Schulte by Peter Luschny, Mar 07 2025
Comments