A366053 Expansion of (1/x) * Series_Reversion( x*(1-x)^4/(1-x+x^3) ).

1, 3, 15, 92, 628, 4579, 34917, 275041, 2220472, 18275896, 152780718, 1293657534, 11072033677, 95629771059, 832460471465, 7296161486583, 64331378963164, 570228657335744, 5078345448484216, 45418278349485960, 407749837317844851, 3673300856466182388

Offset

0,2

Links

Table of n, a(n) for n=0..21.

Formula

a(n) = (1/(n+1)) * Sum_{k=0..floor(n/3)} binomial(n+1,k) * binomial(4*n-2*k+2,n-3*k).

Prog

(PARI) a(n) = sum(k=0, n\3, binomial(n+1, k)*binomial(4*n-2*k+2, n-3*k))/(n+1);

Crossrefs

Cf. A049128, A114997, A366051, A366052.

Sequence in context: A020018 A124553 A369623 * A369114 A020108 A323696

Adjacent sequences: A366050 A366051 A366052 * A366054 A366055 A366056

Keyword

nonn

Author

Seiichi Manyama, Sep 27 2023

Status

approved