cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A337617 T(n, k) = (n + 1)*2^(n + k)*hypergeom([-n, k - n + 1], [2], 1/2), triangle read by rows for 0 <= k <= n.

Original entry on oeis.org

1, 4, 6, 18, 24, 28, 88, 112, 128, 120, 450, 560, 640, 640, 496, 2364, 2904, 3328, 3456, 3072, 2016, 12642, 15400, 17696, 18816, 17920, 14336, 8128, 68464, 82912, 95488, 103168, 102400, 90112, 65536, 32640, 374274, 451296, 520704, 569088, 580608, 540672, 442368, 294912, 130816
Offset: 0

Views

Author

Peter Luschny, Oct 19 2020

Keywords

Examples

			Triangle starts:
[0]                                1
[1]                              4, 6
[2]                           18, 24, 28
[3]                       88, 112, 128, 120
[4]                    450, 560, 640, 640, 496
[5]               2364, 2904, 3328, 3456, 3072, 2016
[6]         12642, 15400, 17696, 18816, 17920, 14336, 8128
[7]    68464, 82912, 95488, 103168, 102400, 90112, 65536, 32640
		

Crossrefs

T(n, n) = A171476(n) = A006516(n+1). T(n, 0) = A050146(n+1).
Cf. A337992 (row sums).

Programs

  • Maple
    T := (n, k) -> simplify((n + 1)*2^(n + k)*hypergeom([-n, k - n + 1], [2], 1/2)): seq(seq(T(n, k), k=0..n), n=0..8);
  • Mathematica
    T[n_,k_] := If[n==k, 2^n*(2^(n+1)-1), 2^(2*k+1)*Sum[(-1)^j*2^(n-k-j)* Binomial[n+1, j]*Binomial[2*n-j-k, n], {j, 0, n-k}]];
    Flatten[Table[T[n,k], {n,0,10}, {k,0,n}]] (* Detlef Meya, Dec 20 2023 *)

Formula

T(n, k) = if n = k then 2^n*(2^(n+1)-1), otherwise 2^(2*k+1)*Sum_{j=0..n-k} ((-1)^j*2^(n-k-j)*binomial(n+1,j)*binomial(2*n-j-k,n)). - Detlef Meya, Dec 20 2023