A284210 Number of subgroups of order n of the symmetric group Sym(n) on n symbols.

1, 1, 1, 7, 6, 280, 120, 25335, 11200, 276696, 362880, 374838255, 39916800, 2414617920, 11721790080

Offset

1,4

Comments

The diagonal of A243748 (once the 0's for non-divisors of n are filled in). - R. J. Mathar, Mar 30 2017

Links

Table of n, a(n) for n=1..15.

Formula

If n is prime, A284210(n) = (n-2)!.

Example

The group Sym(4) contains 3 cyclic groups of order 4, 3 non-normal elementary abelian groups of order 4 and one normal group of order 4, so A284210(4) = 3 + 3 + 1 = 7.

Prog

(GAP) List([1..14], n -> Sum(List(Filtered(ConjugacyClassesSubgroups(SymmetricGroup(n)), c -> Size(Representative(c)) = n)), c -> Size(c)));

Crossrefs

Sequence in context: A366225 A223531 A130553 * A371078 A002394 A340030

Adjacent sequences: A284207 A284208 A284209 * A284211 A284212 A284213

Keyword

nonn,more

Author

Jens Voß, Mar 23 2017

Status

approved