A261427 Number of permutations p of [7n] without fixed points such that p^7 = Id.

1, 720, 889574400, 24825530695680000, 5290995845684330496000000, 5123434663327851951402516480000000, 16586604100059403377645257954741452800000000, 146550752102252281868362306608987740351496192000000000

Offset

0,2

Links

Alois P. Heinz, Table of n, a(n) for n = 0..73

Formula

a(n) = (7n)! * [x^(7n)] exp(x^7/7).

Maple

a:= proc(n) option remember; `if`(n=0, 1,
      mul(7*n-i, i=1..6)*a(n-1))
    end:
seq(a(n), n=0..10);

Crossrefs

7-section of column k=7 of A261430.

Cf. A053497.

Sequence in context: A208192 A258927 A195390 * A210280 A003926 A172621

Adjacent sequences: A261424 A261425 A261426 * A261428 A261429 A261430

Keyword

nonn

Author

Alois P. Heinz, Aug 18 2015

Status

approved