A366055 Expansion of (1/x) * Series_Reversion( x*(1-x)^3/(1-x+x^4) ).

1, 2, 7, 30, 144, 741, 3996, 22287, 127494, 743919, 4410255, 26489073, 160843708, 985729010, 6089215057, 37875775533, 237021929322, 1491204370335, 9426547131330, 59843910602283, 381378377720469, 2438954925930558, 15646857920046108

Offset

0,2

Links

Table of n, a(n) for n=0..22.

Formula

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

Prog

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

Crossrefs

Cf. A215341, A366054, A366056.

Sequence in context: A368933 A187979 A358964 * A368932 A369160 A243632

Adjacent sequences: A366052 A366053 A366054 * A366056 A366057 A366058

Keyword

nonn

Author

Seiichi Manyama, Sep 27 2023

Status

approved