cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A347007 Number of cycle types of permutation groups with degree n.

Original entry on oeis.org

1, 1, 2, 4, 11, 19, 55, 93, 285, 535, 1514, 2934
Offset: 0

Views

Author

Peter Dolland, Aug 10 2021

Keywords

Comments

A000638 gives the number of permutation groups of degree n. Each permutation group is assigned a cumulative cycle type resulting from the cycle types of its member permutations.

Examples

			The 4 cycle types of the 4 permutation groups with degree 3 may be represented by arrays of length 3 (the number of partitions of 3, A000041(3)), indicating the quantity of member permutations, whose cycle type yields a specific partition of n. The partitions are listed in graded lexicographical ordering (see A193073), here (1^3), (2,1), (3):
   1. [1, 0, 0]
   2. [1, 1, 0]
   3. [1, 0, 2]
   4. [1, 3, 2]
The cycle types belong to the permutation groups {id}, C2, C3, and S3 (all subgroups of S3).
Note: For degree n < 6 all permutation groups have different cycle types, so a(n) = A000638(n). For n = 6 there are exactly two permutation groups with the same cycle type (namely [1, 0, 3, 0, 0, 0, 0, 0, 0, 0, 0], both groups isomorphic with C2^2), so a(6) = 55 = A000638(6) - 1.
		

Crossrefs

Cf. A000638.

Programs

  • GAP
    # GAP 4.11.1
    n := 9;;
    G := SymmetricGroup(n);
    cc := ConjugacyClasses(G);;
    sub := ConjugacyClassesSubgroups(G);;
    rep := List(sub, Representative);;
    ctlst := List( rep, x-> List( cc, c-> Size( Intersection( x, c))));;
    Size( AsDuplicateFreeList( ctlst));