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A274900
Number of (not necessarily proper) vertex colorings of the truncated cube using at most n colors.
3
1, 352744, 5884691769, 5864100125056, 1241764261950625, 98716288267057896, 3991275742289356969, 98382635628154476544, 1661800900370941653561, 20833333346104183585000, 205202764127643987528241, 1656184316900213910466944, 11308349383297867766174569
OFFSET
1,2
LINKS
Marko R. Riedel et al., Truncated objects coloring, Mathematics Stack Exchange (Jul 10 2016).
Wikipedia, Truncated cube
FORMULA
a(n) = 1/48*n^24 + 1/8*n^14 + 13/48*n^12 + 1/6*n^8 + 1/4*n^6 + 1/6*n^4 = n^4*(n^20 + 6*n^10 + 13*n^8 + 8*n^4 + 12*n^2 + 8)/48.
EXAMPLE
Cycle index: 1/48*s[1]^24 + 1/8*s[2]^10*s[1]^4 + 13/48*s[2]^12 + 1/6*s[3]^8 + 1/4*s[4]^6 + 1/6*s[6]^4.
MATHEMATICA
Table[1/48 n^24 + 1/8 n^14 + 13/48 n^12 + 1/6 n^8 + 1/4 n^6 + 1/6 n^4, {n, 25}] (* Vincenzo Librandi, Jul 11 2016 *)
PROG
(Magma) [1/48*n^24+1/8*n^14+13/48*n^12+1/6*n^8+1/4*n^6+1/6*n^4: n in [1..20]]; // Vincenzo Librandi, Jul 11 2016
(PARI) a(n) = 1/48*n^24 + 1/8*n^14 + 13/48*n^12 + 1/6*n^8 + 1/4*n^6 + 1/6*n^4 \\ Felix Fröhlich, Jul 12 2016
CROSSREFS
Sequence in context: A205334 A140942 A294858 * A284081 A050515 A179709
KEYWORD
nonn,easy
AUTHOR
Marko Riedel, Jul 10 2016
STATUS
approved