A351780 a(n) = n! * Sum_{k=0..n} (-k)^(n-k) * (n-k)^k/k!.

1, 0, -2, 6, 108, -2420, 8730, 1313718, -57930152, 567983736, 109544982390, -9917916180590, 321821829728388, 32383946348733252, -6591798188344856942, 531702135210365508270, 11136706526396459006640

Offset: 0

Author

Seiichi Manyama, Feb 19 2022

Keywords

• sign

Crossrefs

Cf. A351768, A351779.

Programs

PARI

a(n) = n!*sum(k=0, n, (-k)^(n-k)*(n-k)^k/k!);