OFFSET
1,2
FORMULA
a(n) = A292898(n, 2).
From Vaclav Kotesovec, Jul 05 2018: (Start)
Recurrence: (n^2 - 4*n + 5)*a(n) = (n^3 - 3*n^2 + 3*n + 2)*a(n-1) - (n-1)*(2*n - 3)*a(n-2) - (n^3 - 3*n^2 + 2*n + 1)*a(n-3) + (n^2 - 2*n + 2)*a(n-4).
a(n) ~ n * n!.
a(n) ~ sqrt(2*Pi) * n^(n + 3/2) / exp(n). (End)
MAPLE
MATHEMATICA
Table[Sum[(-1)^(n-k)*HypergeometricPFQ[{k, k-2-n}, {}, 1], {k, 1, n}], {n, 1, 20}] (* Vaclav Kotesovec, Jul 05 2018 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Oct 05 2017
STATUS
approved