A372020 G.f. A(x) satisfies A(x) = ( 1 + 16*x*A(x)/(1 - x*A(x)) )^(1/4).

1, 4, -4, 4, 156, -1212, 5628, 196, -251620, 2500484, -12608772, 16004, 671151260, -7039845180, 37258827516, 1585476, -2133978944740, 23052545651460, -125166709730820, 174117124, 7480512144282780, -82265332158299580, 453899597102224380, 20390254020

Offset

0,2

Links

Table of n, a(n) for n=0..23.

Formula

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

Prog

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

Crossrefs

Cf. A372018, A372019.

Cf. A372005.

Sequence in context: A077725 A217940 A353000 * A182065 A325487 A239351

Adjacent sequences: A372017 A372018 A372019 * A372021 A372022 A372023

Keyword

sign

Author

Seiichi Manyama, Apr 15 2024

Status

approved