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A097424
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Denominator of Product_{k=1..n} H(k), where H(k) = Sum_{j=1..k} 1/j, the k-th harmonic number.
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2
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1, 2, 4, 48, 576, 2304, 15360, 614400, 1548288000, 3901685760000, 9832248115200000, 24777265250304000000, 62438708430766080000000, 157345545245530521600000000, 5154640062243579887616000000000
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OFFSET
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1,2
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LINKS
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EXAMPLE
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(1)(1 + 1/2)(1 + 1/2 + 1/3) = 1*(3/2)*(11/6) = 11/4, so a(3) = 4.
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MATHEMATICA
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a[n_] := Denominator[ Product[ HarmonicNumber[k], {k, 1, n}]]; Table[ a[n], {n, 14}] (* Robert G. Wilson v, Aug 26 2004 *)
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PROG
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(PARI) hh(n)=sum(i=1, n, 1/i); ff(n)=denominator(prod(i=1, n, hh(i))); for (i=1, 30, print1(ff(i), ", ")) \\ Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com), Aug 23 2004
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CROSSREFS
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KEYWORD
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frac,nonn
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AUTHOR
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EXTENSIONS
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More terms from Mohammed Bouayoun (mohammed.bouayoun(AT)sanef.com) and Robert G. Wilson v, Aug 23 2004
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STATUS
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approved
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