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A334585
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Denominator of Sum_{k=1..n} (-1)^(k+1)/k^4.
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3
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1, 16, 1296, 20736, 12960000, 4320000, 10372320000, 165957120000, 40327580160000, 8065516032000, 118087220224512000, 118087220224512000, 3372689096832287232000, 3372689096832287232000, 16863445484161436160000, 269815127746582978560000, 22535229284522356952309760000
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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The first few fractions are 1, 15/16, 1231/1296, 19615/20736, 12280111/12960000, 4090037/4320000, 9824498837/10372320000, ... = A120296/A334585.
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MAPLE
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b := proc(n) local k: add((-1)^(k + 1)/k^4, k = 1 .. n): end proc:
seq(denom(b(n)), n = 1 .. 17);
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MATHEMATICA
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Denominator @ Accumulate[Table[(-1)^(k + 1)/k^4, {k, 1, 17}]] (* Amiram Eldar, May 08 2020 *)
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PROG
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(PARI) a(n) = denominator(sum(k=1, n, (-1)^(k+1)/k^4)); \\ Michel Marcus, May 07 2020
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CROSSREFS
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KEYWORD
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nonn,frac
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AUTHOR
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STATUS
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approved
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