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A068550
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a(n) = lcm{1, ..., 2n} / binomial(2n, n).
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4
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1, 1, 2, 3, 12, 10, 30, 105, 56, 252, 1260, 330, 1980, 2574, 2002, 15015, 240240, 61880, 15912, 151164, 38760, 406980, 4476780, 1144066, 13728792, 24515700, 6249100, 84362850, 21474180, 5462730, 81940950, 1270084725, 645122400
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OFFSET
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0,3
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COMMENTS
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Known to be always an integer.
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LINKS
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Table of n, a(n) for n=0..32.
Hojoo Lee, Re: LCM [1,2,..,N] > 2^{N-1}, NMBRTHRY Mailing List, Feb 18 2002.
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FORMULA
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a(n) = A099996(n) / A000984(n) = A003418(2*n) / A001405(2*n) = A180000(2*n) = A263673(2*n).
a(n) = n * A068553(n) = n * A048619(2*n-1).
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CROSSREFS
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Bisection of A180000 and A263673.
Sequence in context: A027611 A303221 A168059 * A093432 A212303 A100561
Adjacent sequences: A068547 A068548 A068549 * A068551 A068552 A068553
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KEYWORD
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nonn,easy
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AUTHOR
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N. J. A. Sloane, Mar 23 2002
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EXTENSIONS
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a(0)=1 prepended by Max Alekseyev, Oct 23 2015
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STATUS
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approved
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