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A350721
a(n) = Sum_{k=0..n} k! * k^(k+n) * Stirling1(n,k).
10
1, 1, 31, 4184, 1495534, 1110325474, 1481505320078, 3225820132807320, 10696978730747904696, 51287741246274865567776, 341442095880058160040860592, 3055472627228313328903357352784, 35788671820468495762774011478900032
OFFSET
0,3
LINKS
FORMULA
E.g.f.: Sum_{k>=0} (k * log(1 + k*x))^k.
a(n) ~ exp(-exp(-2)/2) * n! * n^(2*n). - Vaclav Kotesovec, Feb 04 2022
MATHEMATICA
a[0] = 1; a[n_] := Sum[k! * k^(k+n) * StirlingS1[n, k], {k, 1, n}]; Array[a, 13, 0] (* Amiram Eldar, Feb 03 2022 *)
PROG
(PARI) a(n) = sum(k=0, n, k!*k^(k+n)*stirling(n, k, 1));
(PARI) my(N=20, x='x+O('x^N)); Vec(serlaplace(sum(k=0, N, (k*log(1+k*x))^k)))
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Feb 03 2022
STATUS
approved