A306193 a(n) = Product_{k=0..n} (1 + n!/k!).

2, 4, 18, 392, 81250, 225061452, 9854913828914, 7821195286733052688, 128042318400630042200896962, 48734103316428964151516768659332500, 480771737247108575104717059364582638896056402, 135700420467061659867201490569546772642393389614560348824

Offset

0,1

Links

Table of n, a(n) for n=0..11.

Formula

a(n) = A323717(n) / A000178(n).

a(n) ~ 2 * A * n^(n*(n+1)/2 + 1/12) / exp(n^2/4), where A is the Glaisher-Kinkelin constant A074962.

Mathematica

Table[Product[1 + n!/k!, {k, 0, n}], {n, 0, 12}]

Crossrefs

Cf. A000178, A269700, A323717.

Sequence in context: A318394 A228933 A347514 * A323702 A318531 A009667

Adjacent sequences: A306190 A306191 A306192 * A306194 A306195 A306196

Keyword

nonn

Author

Vaclav Kotesovec, Jan 28 2019

Status

approved