A371893 G.f. A(x) satisfies A(x) = 1 + x/A(x)^2 * (1 + A(x)^4).

1, 2, 0, 16, -32, 336, -1472, 10944, -63744, 441088, -2866688, 19772416, -134832128, 941381632, -6585720832, 46607831040, -331406262272, 2373110628352, -17072541007872, 123438375763968, -896088779128832, 6530356893777920, -47752086733717504

Offset

0,2

Links

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

Formula

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

Prog

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

Crossrefs

Cf. A364393, A364394, A364396, A364397, A366364.

Sequence in context: A057375 A009045 A060313 * A015154 A346119 A009266

Adjacent sequences: A371890 A371891 A371892 * A371894 A371895 A371896

Keyword

sign

Author

Seiichi Manyama, Apr 11 2024

Status

approved