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1, 1, 0, 1, 3, 1, 3, 3, 10, 18, 12, 26, 39, 57, 59, 116, 201, 219, 325, 416, 625, 810, 1074, 1447, 2345, 3078, 3530, 5084, 6790, 9063, 11674, 15580, 20887, 27537, 33640, 45065, 61297, 76883, 96889, 126243, 169268, 210005, 262068, 337445, 438197, 552346, 686794, 865904, 1128611, 1407533, 1732572
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refs;
listen;
history;
text;
internal format)
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OFFSET
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0,5
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LINKS
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FORMULA
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a(n) = sum((-1)^(n-k)*p(n,k)^2,k=0..n), where p(n,k) is the number of partitions of n into k positive parts (A072233, A008284).
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MATHEMATICA
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pnkList[n_] := Table[Length[IntegerPartitions[n, {k}]], {k, 0, n}]
Table[Total[Table[(-1)^(n-k), {k, 0, n}] Map[#^2 &, pnkList[n]]], {n, 0, 50}]
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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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