OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..n} binomial(n,k) * Bell(2*n-k) * n^k.
MATHEMATICA
Table[Exp[-1] Sum[(k (k + n))^n/k!, {k, 0, Infinity}], {n, 0, 15}]
Join[{1}, Table[Sum[Binomial[n, k] BellB[2 n - k] n^k, {k, 0, n}], {n, 1, 15}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 22 2021
STATUS
approved