A371990 G.f. A(x) satisfies A(x) = ( 1 + 16*x*A(x)*(1 + A(x)) )^(1/4).

1, 8, 0, -256, 2048, 8192, -327680, 2097152, 27262976, -612368384, 2013265920, 82409684992, -1249835483136, -996432412672, 239418656948224, -2495891395051520, -17018240974716928, 669901648478339072, -4349632815109767168, -80937285128219000832

Offset

0,2

Links

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

Formula

a(n) = 16^n * Sum_{k=0..n} binomial(n,k) * binomial(n/4+k/4+1/4,n)/(n+k+1).

Prog

(PARI) a(n) = 16^n*sum(k=0, n, binomial(n, k)*binomial(n/4+k/4+1/4, n)/(n+k+1));

Crossrefs

Cf. A000302, A371989.

Sequence in context: A221379 A013376 A221421 * A013456 A180738 A076107

Adjacent sequences: A371987 A371988 A371989 * A371991 A371992 A371993

Keyword

sign

Author

Seiichi Manyama, Apr 15 2024

Status

approved