OFFSET
0,8
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..1000
FORMULA
a(n) = (4 * a(n-1) - n * a(n-5) + 1)/5 for n > 4.
PROG
(PARI) a(n) = sum(k=0, n\5, (-1)^k*(n-4*k)!/(n-5*k)!);
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Nov 23 2022
STATUS
approved