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A306096
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Number of plane partitions of n where parts are colored in (at most) 6 colors.
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4
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1, 6, 78, 726, 7278, 62574, 586878, 4889166, 42892710, 354335982, 2976581670, 23990771094, 197564663094, 1565310230790, 12548473437822, 98526949264374, 776195574339102, 6008457242324814, 46729763436714126, 357901583160822990, 2748384845416097718
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OFFSET
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0,2
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COMMENTS
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a(0) = 1 corresponds to the empty sum, in which all terms are colored in one among six given colors, since there is no term at all.
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LINKS
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FORMULA
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a(n) = Sum_{k=1..n} A091298(n,k)*6^k, for n > 0.
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EXAMPLE
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For n = 1, there is only the partition [1], which can be colored in any of the six colors, whence a(1) = 6.
For n = 2, there are the partitions [2], [1,1] and [1;1]. Adding colors, this yields a(2) = 6 + 36 + 36 = 78 distinct possibilities.
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PROG
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(PARI) a(n)=sum(k=1, n, A091298(n, k)*6^k, !n)
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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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