A395657 Expansion of 1/(16*x) * (1/(5-4*g)^4 - 1), where g = 1+x*g^5 is the g.f. of A002294.

1, 15, 215, 2995, 40914, 551005, 7340200, 96943515, 1271426915, 16578465406, 215115348570, 2779579995425, 35785838757200, 459266020152120, 5877599725713264, 75033029204530155, 955728484127802825, 12149038561177186525, 154154652693004201225, 1952762911533701935206

Offset

0,2

Links

Table of n, a(n) for n=0..19.

Formula

a(n) = A395660(n)/(n+1) = (1/(n+1)) * Sum_{k=0..n} 4^k * binomial(k+4,4) * binomial(5*n+5,n-k).

Prog

(PARI) a(n) = sum(k=0, n, 4^k*binomial(k+4, 4)*binomial(5*n+5, n-k))/(n+1);

Crossrefs

Cf. A001700, A395655, A395656.

Cf. A002294, A359660.

Sequence in context: A179091 A201340 A051826 * A351515 A081196 A020287

Adjacent sequences: A395654 A395655 A395656 * A395658 A395659 A395660

Keyword

nonn

Author

Seiichi Manyama, May 02 2026

Status

approved