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A337952
Number of oriented colorings of the 16 tetrahedral facets of a hyperoctahedron or of the 16 vertices of a tesseract.
8
1, 496, 230076, 22456756, 795467350, 14697611496, 173107727191, 1466088119056, 9651378868011, 52083991149400, 239323201136866, 962942859342036, 3465720389989936, 11343525530430016, 34210497067620525
OFFSET
1,2
COMMENTS
Each chiral pair is counted as two when enumerating oriented arrangements. The Schläfli symbols for the tesseract and the hyperoctahedron are {4,3,3} and {3,3,4} respectively. Both figures are regular 4-D polyhedra and they are mutually dual. There are 192 elements in the rotation group of the tesseract. Each involves a permutation of the axes that can be associated with a partition of 4 based on the conjugacy class of the permutation. This table shows the cycle indices for each rotation by partition. The first formula is obtained by averaging these cycle indices after replacing x_i^j with n^j according to the Pólya enumeration theorem.
Partition Count Even Cycle Indices
4 6 8x_8^2
31 8 4x_1^4x_3^4 + 4x_2^2x_6^2
22 3 4x_1^4x_2^6 + 4x_4^4
211 6 4x_2^8 + 4x_4^4
1111 1 x_1^16 + 7x_2^8
LINKS
Index entries for linear recurrences with constant coefficients, signature (17, -136, 680, -2380, 6188, -12376, 19448, -24310, 24310, -19448, 12376, -6188, 2380, -680, 136, -17, 1).
FORMULA
a(n) = n^2 * (n^14 + 12*n^8 + 63*n^6 + 68*n^2 + 48) / 192.
a(n) = 1*C(n,1) + 494*C(n,2) + 228591*C(n,3) + 21539424*C(n,4) + 685479375*C(n,5) + 10257064650*C(n,6) + 86151316860*C(n,7) + 449772354360*C(n,8) + 1551283253100*C(n,9) + 3661969537800*C(n,10) + 6015983173200*C(n,11) + 6878457986400*C(n,12) + 5371454088000*C(n,13) + 2733402672000*C(n,14) + 817296480000*C(n,15) + 108972864000*C(n,16), where the coefficient of C(n,k) is the number of oriented colorings using exactly k colors.
a(n) = A128767(n) + A337954(n) = 2*A128767(n) - A337955(n) = 2*A337954(n) + A337955(n).
MATHEMATICA
Table[(n^16+12n^10+63n^8+68n^4+48n^2)/192, {n, 30}]
CROSSREFS
Cf. A128767 (unoriented), A337954 (chiral), A337955 (achiral).
Other elements: A331358 (tesseract edges, hyperoctahedron faces), A331354 (tesseract faces, hyperoctahedron edges), A337956 (tesseract facets, hyperoctahedron vertices).
Other polychora: A337895 (4-simplex facets/vertices), A338948 (24-cell), A338964 (120-cell, 600-cell).
Row 4 of A325012 (orthoplex facets, orthotope vertices).
Sequence in context: A110847 A160472 A028512 * A088845 A013685 A108157
KEYWORD
nonn,easy
AUTHOR
Robert A. Russell, Oct 03 2020
STATUS
approved