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.

A198861 The number of ways to paint the faces of the five Platonic solids using exactly n colors where n is the number of faces of each solid.

Original entry on oeis.org

2, 30, 1680, 7983360, 40548366802944000
Offset: 1

Views

Author

Geoffrey Critzer, Oct 30 2011

Keywords

Comments

Let G, the group of rotations in 3 dimensional space act on the set of n! paintings of each Platonic solid having n faces. There are n! fixed points in the action table since the only element in G that leaves a painting fixed is the identity element. The order of G is A098427/2. So by Burnside's Lemma a(n)=n!/|G|.

Crossrefs

Cf. A053016 (number of faces), A063722 (number of edges).

Programs

  • PARI
    lista() = {ve = [6, 12, 12, 30, 30 ]; vf = [4, 6, 8, 12, 20 ]; for (i=1, 5, nb = vf[i]!/(2*ve[i]); print1(nb, ", "););} \\ Michel Marcus, Aug 25 2014

Formula

a(n) = A053016(n)!/(2*A063722(n)) (see link). - Michel Marcus, Aug 24 2014