A382781 Sum of GCD of cycle lengths over all permutations of [n] with distinct cycle lengths.

0, 1, 2, 9, 32, 170, 1164, 7434, 62880, 582336, 5875200, 60041520, 841501440, 9440926560, 141618778560, 2222190784800, 34862691548160, 543348318159360, 11173101312844800, 186494289764106240, 4219768887634944000, 86094733814301542400, 1834643656963469721600

Offset: 0

Author

Alois P. Heinz, May 11 2025

Keywords

• nonn

Examples

			a(3) = 9 = 3+3+1+1+1: (123), (132), (1)(23), (13)(2), (12)(3).
		

Links

• Alois P. Heinz, Table of n, a(n) for n = 0..450
• Wikipedia, Permutation

Crossrefs

Cf. A000142, A007838, A346066, A382780.

Programs

Maple

b:= proc(n, i, m) option remember; `if`(i*(i+1)/2 b(n$2, 0):
seq(a(n), n=0..22);