OFFSET
0,2
FORMULA
a(n) ~ sqrt(1 + LambertW(exp(-1))) * (2-mod(n,2))^n * n^n / ((1 - LambertW(exp(-1))) * exp(n) * LambertW(exp(-1))^(n + 1/(2-mod(n,2)))). - Vaclav Kotesovec, Jun 02 2023
MAPLE
a := n -> add(add(binomial(k, j) * ((2 - irem(n, 2)) * j + 1)^n, j = 0..k) * 2^(n - k), k = 0..n): seq(a(n), n = 0..17);
MATHEMATICA
Table[Sum[2^(n-k) * Sum[Binomial[k, j]*((2 - Mod[n, 2])*j + 1)^n, {j, 0, k}], {k, 0, n}], {n, 0, 20}] (* Vaclav Kotesovec, Jun 02 2023 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Jun 02 2023
STATUS
approved