A026934 a(n) = Sum_{k=0..n-1} T(n,k) * T(n,k+1), with T given by A008288.

1, 6, 35, 196, 1093, 6090, 33991, 190152, 1066313, 5993422, 33759851, 190538380, 1077316493, 6101144722, 34603634063, 196524445840, 1117492252561, 6361505951382, 36251199646387, 206773994830164, 1180452564195797, 6744529721551450, 38563791929450071, 220652949570236760

Offset

1,2

Links

G. C. Greubel, Table of n, a(n) for n = 1..500

Mathematica

A008288[n_, k_]:= Binomial[n, k]*Hypergeometric2F1[-k, k-n, -n, -1];
A026934[n_]:= Sum[A008288[n, k]*A008288[n, k+1], {k, 0, n-1}];
Table[A026934[n], {n, 1, 40}] (* G. C. Greubel, May 25 2021 *)

Prog

(Sage)
@CachedFunction
def A008288(n, k): return sum(binomial(n-j, j)*binomial(n-2*j, k-j) for j in (0..k))
def A026934(n): return sum(A008288(n, k)*A008288(n, k+1) for k in (0..n-1))
[A026934(n) for n in (1..40)] # G. C. Greubel, May 25 2021

Crossrefs

Cf. A008288.

Sequence in context: A346318 A009572 A027202 * A171311 A230713 A131435

Adjacent sequences: A026931 A026932 A026933 * A026935 A026936 A026937

Keyword

nonn

Author

Clark Kimberling

Extensions

More terms from Sean A. Irvine, Oct 17 2019

Status

approved