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Search: id:A005038
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| A005038 |
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Number of ways of dissecting a polygon into n hexagons.
(Formerly M2026)
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+0
3
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| 1, 1, 2, 12, 57, 366, 2340, 16252, 115940, 854981, 6444826, 49554420, 387203390, 3068067060, 24604111560, 199398960212, 1631041938108, 13451978877748
(list; graph; listen)
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OFFSET
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1,3
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
F. Harary, E. M. Palmer and R. C. Read, On the cell-growth problem for arbitrary polygons, Discr. Math. 11 (1975), 371-389.
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MATHEMATICA
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p=5; Table[Binomial[(p-1)n, n]/(((p-2)n+1)((p-2)n+2)) +If[OddQ[n], 0, Binomial[(p-1)n/2, n/2]/((p-2)n+2)]+Plus @@ Map[EulerPhi[ # ]Binomial[((p-1)n+1)/#, (n-1)/# ]/((p-1)n+1)&, Complement[Divisors[GCD[p, n-1]], {1}]], {n, 1, 20}] - Robert A. Russell (russell(AT)post.harvard.edu), Dec 11 2004
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CROSSREFS
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Sequence in context: A105487 A098453 A067125 this_sequence A094780 A100103 A054145
Adjacent sequences: A005035 A005036 A005037 this_sequence A005039 A005040 A005041
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KEYWORD
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nonn
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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