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A320235
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G.f.: Product_{k>=1, j>=1} (1 + x^(k*j))^2.
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4
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1, 2, 5, 12, 24, 48, 94, 172, 310, 550, 946, 1602, 2679, 4394, 7123, 11424, 18082, 28344, 44039, 67754, 103412, 156660, 235489, 351602, 521650, 768998, 1127100, 1642946, 2381929, 3436028, 4932998, 7049004, 10028422, 14207122, 20044327, 28169528, 39439899
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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(n*log(n)/3).
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MATHEMATICA
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nmax = 50; CoefficientList[Series[Product[(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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