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Search: id:A089512
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| A089512 |
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Denominators used in the computation of the column sequences of array A078739 ((2,2)-Stirling2). |
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+0
2
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| 1, 2, 1, 18, 6, 360, 90, 12600, 2520, 680400, 113400, 52390800, 7484400, 5448643200, 681080400, 735566832000, 81729648000, 125046361440000, 12504636144000, 26134689540960000, 2375880867360000, 6585941764321920000
(list; graph; listen)
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OFFSET
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2,2
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COMMENT
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See A089511 for the column sequence computation of A078739.
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FORMULA
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a(n)=LCM(seq(denominator(b(n, m)), m=1..n-1)), n>=2, where b(n, m) is defined like A089511(n, m) but without the factor D(n) and LCM stands for the least common multiple of a set of numbers.
a(n)=(sqrt(2)*n!/(8*2^(n/2)))*((n^2+4n+2*sqrt(2)+3)-(n^2+4n-2*sqrt(2)+3)*(-1)^n) [offset 0]. - Paul Barry (pbarry(AT)wit.ie), Sep 04 2007
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CROSSREFS
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Sequence in context: A013072 A012895 A013077 this_sequence A089014 A063426 A070890
Adjacent sequences: A089509 A089510 A089511 this_sequence A089513 A089514 A089515
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KEYWORD
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nonn,easy
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AUTHOR
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Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Dec 01 2003
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