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A283049
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Numbers of configurations of A'Campo forests with co-dimension 1 and degree n>0.
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4
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0, 4, 48, 480, 4560, 42504, 393120, 3624768, 33390720, 307618740, 2835722032, 26162863584, 241614915360, 2233533229200, 20667453710400, 191422799835264, 1774573628661504, 16465220088660432, 152894968403313600, 1420856831349155200, 13213537097286612240
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OFFSET
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0,2
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COMMENTS
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We can prove this using generating functions. a(n) is given also by 4*binomial(4n,n-2), for n>1.
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LINKS
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FORMULA
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a(n) = 4*binomial(4n,n-2), for n>1.
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EXAMPLE
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For n=2 the a(2)=4 solutions are the number of A'Campo forests with co-dimension 1 and degree 2.
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MATHEMATICA
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Table[4*Binomial[4n, n-2], {n, 1, 23}] (* Indranil Ghosh, Feb 28 2017 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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