OFFSET
0,2
PROG
(PARI) a(n) = sum(k=0, n, sum(j=0, n-k, binomial(j+k, k)*abs(stirling(n, j+k, 1))*(k+2)^j)); \\ Michel Marcus, Apr 15 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Apr 15 2019
STATUS
approved