A246292 Number of permutations on [n*(n+1)/2] with cycles of n distinct lengths.

1, 1, 3, 120, 151200, 10897286400, 70959641905152000, 60493719168990845337600000, 9226024969987629401488081551360000000, 329646772667218349211759153151614073700352000000000, 3498788402132461399351052923160966975192989707740695756800000000000

Offset

0,3

Links

Alois P. Heinz, Table of n, a(n) for n = 0..30

Formula

a(n) = C(n+1,2)! / n!.

a(n) = A218868(n*(n+1)/2,n) = A218868(A000217(n),n).

a(n) = A242027(n*(n+1)/2,n) = A242027(A000217(n),n).

a(n) = A022915(n) * A000178(n-1) for n>0.

Maple

a:= n-> binomial(n+1, 2)!/n!:
seq(a(n), n=0..12);

Crossrefs

Cf. A000142, A000178, A000217, A022915, A218868, A242027, A317165.

Sequence in context: A307936 A308142 A289704 * A202768 A289986 A301559

Adjacent sequences: A246289 A246290 A246291 * A246293 A246294 A246295

Keyword

nonn

Author

Alois P. Heinz, Aug 21 2014

Status

approved