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A280422
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G.f.: Product_{k>=1} (1 + x^k) / (1 - x^(k*(k+1)/2)).
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2
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1, 2, 3, 6, 9, 13, 21, 30, 41, 59, 81, 108, 147, 195, 253, 333, 431, 549, 704, 892, 1119, 1409, 1758, 2176, 2697, 3321, 4065, 4976, 6061, 7345, 8898, 10737, 12901, 15489, 18535, 22103, 26333, 31284, 37056, 43844, 51751, 60931, 71655, 84090, 98464, 115162
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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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a(n) ~ exp(sqrt(n/3)*Pi + 3^(1/4) * Zeta(3/2) * n^(1/4) - 3*Zeta(3/2)^2/(8*Pi)) / (32 * 3^(3/4) * n^(5/4)).
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MATHEMATICA
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nmax=60; CoefficientList[Series[Product[(1+x^k)/(1-x^(k*(k+1)/2)), {k, 1, nmax}], {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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