A163089 n! / (Product{k|n} k$). Here '$' denotes the swinging factorial function (A056040).

1, 1, 1, 1, 2, 4, 3, 36, 48, 96, 240, 14400, 2160, 518400, 90720, 141120, 1935360, 1625702400, 870912, 131681894400, 145152000, 15676416000, 287400960000, 1593350922240000, 14780620800, 7648084426752000, 1614043791360000

Offset

0,5

Links

Table of n, a(n) for n=0..26.

Peter Luschny, Swinging Primes.

Maple

a := n -> n! / A163087(n):

Mathematica

sf[n_] := With[{f = Floor[n/2]}, Pochhammer[f+1, n-f]/f!]; a[0] = 1; a[n_] := n!/Product[sf[k], {k, Divisors[n]}]; Table[a[n], {n, 0, 26}] (* Jean-François Alcover, Jul 26 2013 *)

Crossrefs

Cf. A163087, A163088.

Sequence in context: A071970 A182103 A303053 * A258371 A111172 A173556

Adjacent sequences: A163086 A163087 A163088 * A163090 A163091 A163092

Keyword

nonn

Author

Peter Luschny, Jul 21 2009

Status

approved