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A051540
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Least common multiple of {2, 5, 8, 11, 14, ..., 3n+2} (A016789).
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5
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2, 10, 40, 440, 3080, 52360, 52360, 1204280, 15655640, 454013560, 1816054240, 1816054240, 34505030560, 1414706252960, 1414706252960, 66491193889120, 332455969445600, 17620166380616800, 17620166380616800
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OFFSET
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0,1
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COMMENTS
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Denominator of H(n,3,2), a generalized harmonic number. See A075135.
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LINKS
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EXAMPLE
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a(3) = lcm{2, 5, 8, 11} = 440.
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MAPLE
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A[0]:= 2:
for n from 1 to 60 do A[n]:= ilcm(A[n-1], 3*n+2) od:
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MATHEMATICA
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Table[ Denominator[ Sum[1/i, {i, 2/3, n}]], {n, 1, 20}]
Table[ Apply[ LCM, Join[{1}, Table[2 + 3i, {i, 0, n}]]], {n, 0, 19}]
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PROG
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(Magma) k:=56; [Lcm([h: h in [2..j by 3]]): j in [2..k by 3]]; // Bruno Berselli, May 03 2011
(PARI) a(n) = lcm(vector(n+1, k, 3*k-1)); \\ Michel Marcus, Apr 10 2018
(GAP) List([0..20], n->Lcm(List([0..n], k->3*k+2))); # Muniru A Asiru, Apr 14 2018
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CROSSREFS
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KEYWORD
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easy,frac,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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