OFFSET
0,4
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..196
FORMULA
a(n) = Sum_{k=0..n} (-k^4)^(n-k).
MATHEMATICA
a[n_] := Sum[If[k == n - k == 0, 1, (-k^4)^(n-k)], {k, 0, n}]; Array[a, 17, 0] (* Amiram Eldar, Dec 03 2021 *)
PROG
(PARI) a(n, s=0, t=4) = sum(k=0, n, (-k^t)^(n-k)*k^s);
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1+k^4*x)))
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Dec 02 2021
STATUS
approved