OFFSET
0,4
FORMULA
a(n) = Sum_{k=0..n} (2*n-k)!/(2*n-2*k+1)! * Stirling1(n,k).
PROG
(PARI) a(n) = sum(k=0, n, (2*n-k)!/(2*n-2*k+1)!*stirling(n, k, 1));
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Nov 08 2023
STATUS
approved