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.

A338948 Number of oriented colorings of the 24 octahedral facets (or 24 vertices) of the 4-D 24-cell using subsets of a set of n colors.

Original entry on oeis.org

1, 30968, 490710246, 488689596200, 103480643539150, 8226360697111116, 332606338581801018, 8198553131754111456, 138483409168412322525, 1736111115543474313600, 17100230356306262961356, 138015359782116886130568
Offset: 1

Views

Author

Robert A. Russell, Nov 17 2020

Keywords

Comments

Each chiral pair is counted as two when enumerating oriented arrangements. The Schläfli symbol of the 24-cell is {3,4,3}. It is self-dual. There are 576 elements in the rotation group of the 24-cell. They divide into 20 conjugacy classes. The first formula is obtained by averaging the vertex (or facet) cycle indices after replacing x_i^j with n^j according to the Pólya enumeration theorem.
Count Even Cycle Indices Count Even Cycle Indices
1 x_1^24 36 x_2^2x_4^5
18 x_1^4x_2^10 32 x_2^3x_6^3
72 x_1^2x_2^11 6+6 x_4^6
1 x_2^12 8+8+32 x_6^4
32 x_1^6x_3^6 72+72 x_8^3
36 x_1^4x_4^5 48+48 x_12^2
8+8+32 x_3^8

Crossrefs

Cf. A338949 (unoriented), A338950 (chiral), A338951 (achiral), A338952 (edges, faces), A337895 (5-cell), A337952 (8-cell vertices, 16-cell facets), A337956 (16-cell vertices, 8-cell facets), A338964 (120-cell, 600-cell).

Programs

  • Mathematica
    Table[(96n^2+144n^3+48n^4+44n^6+36n^7+48n^8+36n^9+33n^12+72n^13+18n^14+n^24)/576,{n,15}]

Formula

a(n) = (96*n^2 + 144*n^3 + 48*n^4 + 44*n^6 + 36*n^7 + 48*n^8 + 36*n^9 + 33*n^12 + 72*n^13 + 18*n^14 + n^24) / 576.
a(n) = 1*C(n,1) + 30966*C(n,2) + 490617345*C(n,3) + 486726941020*C(n,4) + 101042102350935*C(n,5) + 7612797366078810*C(n,6) + 277177820254686645*C(n,7) + 5762279787373449480*C(n,8) + 75992221900428179850*C(n,9) + 682000715348622816300*C(n,10) + 4372841482811937689400*C(n,11) + 20731958137729666674000*C(n,12) + 74473828855001644068000*C(n,13) + 206154110634594043521600*C(n,14) + 444564429725793817440000*C(n,15) + 751083930907369899840000*C(n,16) + 994782360855398955840000*C(n,17) + 1027991414661948696960000*C(n,18) + 819571017352669021440000*C(n,19) + 494068244672052610560000*C(n,20) + 217722453472796912640000*C(n,21) + 66156028946382735360000*C(n,22) + 12387424687382384640000*C(n,23) + 1077167364120207360000*C(n,24), where the coefficient of C(n,k) is the number of oriented colorings using exactly k colors.
a(n) = A338949(n) + A338950(n) = 2*A338949(n) - A338951(n) = 2*A338950(n) + A338951(n).