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A358606
a(n) = Sum_{k=0..floor(n/5)} (-1)^k * (n-4*k)!/(n-5*k)!.
4
1, 1, 1, 1, 1, 0, -1, -2, -3, -4, -3, 0, 5, 12, 21, 26, 21, 0, -43, -114, -195, -244, -195, 42, 581, 1440, 2421, 2990, 2157, -1644, -9955, -22974, -37515, -44248, -24219, 50310, 205661, 442140, 689997, 740906, 190245, -1534224, -4941355, -9887058, -14429619, -13255900, 3510141
OFFSET
0,8
LINKS
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