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A320236
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G.f.: Product_{k>=1, j>=1} 1/(1 - x^(k*j))^2.
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5
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1, 2, 7, 16, 41, 86, 193, 384, 787, 1504, 2899, 5338, 9852, 17586, 31330, 54490, 94350, 160370, 271171, 451776, 748460, 1225106, 1993860, 3212378, 5146851, 8175114, 12915747, 20252564, 31595134, 48964310, 75515995, 115777684, 176696336, 268231986, 405436258
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OFFSET
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0,2
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COMMENTS
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LINKS
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FORMULA
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Conjecture: log(a(n)) ~ Pi * sqrt(2*n*log(n)/3).
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MATHEMATICA
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nmax = 50; CoefficientList[Series[Product[1/(1-x^(k*j))^2, {k, 1, nmax}, {j, 1, Floor[nmax/k] + 1}], {x, 0, nmax}], x]
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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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