OFFSET
0,3
LINKS
Winston de Greef, Table of n, a(n) for n = 0..385
FORMULA
a(n) = Sum_{k=0..floor(n/2)} (n-k)^(n-k) * binomial(n-k,k).
a(n) ~ exp(exp(-1)) * n^n. - Vaclav Kotesovec, Feb 14 2023
MATHEMATICA
Flatten[{1, Table[Sum[Binomial[n-k, k] * (n-k)^(n-k), {k, 0, n/2}], {n, 1, 20}]}] (* Vaclav Kotesovec, Feb 14 2023 *)
PROG
(PARI) my(N=20, x='x+O('x^N)); Vec(sum(k=0, N, (k*x*(1+x))^k))
(PARI) a(n) = sum(k=0, n\2, (n-k)^(n-k)*binomial(n-k, k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 14 2023
STATUS
approved