OFFSET
0,2
FORMULA
a(n) = Sum_{k=0..2*n+1} k!*Stirling2(2*n+1,k).
a(n) = A000670(2*n+1).
a(n) ~ sqrt(Pi) * 2^(2*n + 1) * n^(2*n + 3/2) / (exp(2*n) * (log(2))^(2*n + 2)). - Vaclav Kotesovec, Sep 25 2019
MATHEMATICA
Table[Sum[k^(2 n + 1)/2^(k + 1), {k, 0, Infinity}], {n, 0, 14}]
Table[Sum[k! StirlingS2[2 n + 1, k], {k, 0, 2 n + 1}], {n, 0, 14}]
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jun 29 2019
STATUS
approved