A358604 a(n) = Sum_{k=0..floor(n/3)} (-1)^k * (n-2*k)!/(n-3*k)!.

1, 1, 1, 0, -1, -2, -1, 2, 7, 8, -1, -26, -49, -28, 103, 314, 359, -344, -2113, -3682, -161, 14684, 36791, 25762, -100297, -373456, -472241, 587846, 3877487, 7149988, -1111801, -40808566, -103472249, -56751688, 424662623, 1490284654, 1674543359, -4121143444

Offset

0,6

Links

Seiichi Manyama, Table of n, a(n) for n = 0..1000

Formula

a(n) = (2 * a(n-1) - n * a(n-3) + 1)/3 for n > 2.

Prog

(PARI) a(n) = sum(k=0, n\3, (-1)^k*(n-2*k)!/(n-3*k)!);

Crossrefs

Cf. A358603, A358605, A358606.

Cf. A357532.

Sequence in context: A241738 A021051 A113246 * A192266 A056887 A360025

Adjacent sequences: A358601 A358602 A358603 * A358605 A358606 A358607

Keyword

sign

Author

Seiichi Manyama, Nov 23 2022

Status

approved