OFFSET
0,3
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..386
FORMULA
G.f.: ( Sum_{k>=0} (k * x)^k )/(1 - x^2).
MATHEMATICA
a[n_] := Sum[If[2*k == n, 1, (n - 2*k)^(n - 2*k)], {k, 0, Floor[n/2]}]; Array[a, 20, 0] (* Amiram Eldar, Apr 16 2022 *)
PROG
(PARI) a(n) = sum(k=0, n\2, (n-2*k)^(n-2*k));
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k*x)^k)/(1-x^2))
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Apr 16 2022
STATUS
approved