A366054 Expansion of (1/x) * Series_Reversion( x*(1-x)^2/(1-x+x^4) ).

1, 1, 2, 5, 15, 49, 168, 594, 2149, 7919, 29627, 112254, 429884, 1661308, 6470678, 25375070, 100106145, 397018815, 1582005849, 6330533220, 25428891084, 102497788194, 414445390730, 1680617637425, 6833083703094, 27849689394894, 113762630541908

Offset

0,3

Links

Table of n, a(n) for n=0..26.

Formula

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

Prog

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

Crossrefs

Cf. A215341, A366055, A366056.

Sequence in context: A149935 A149936 A189176 * A369631 A063021 A364833

Adjacent sequences: A366051 A366052 A366053 * A366055 A366056 A366057

Keyword

nonn

Author

Seiichi Manyama, Sep 27 2023

Status

approved