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Search: id:A078973
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| A078973 |
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Total dimension of the homology of a free 2-step nilpotent Lie algebra of rank n. |
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+0
1
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| 2, 6, 36, 420, 9800, 452760, 41835024, 7691667984, 2828336198688, 2073619375892064, 3040584296923128384, 8898500292240756664896, 52084270468105185237918848, 608812309050346291991694422400
(list; graph; listen)
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OFFSET
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1,1
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FORMULA
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a(n) = 2^ceil(n/2)*f(floor((n-1)/2))*f(floor(n/2)), where f(n)= Product_{1<=i<=n} (4*i)!*i!^2/((2*i)!)^3.
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MAPLE
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f := proc(n) local i: mul((4*i)!*i!^2/((2*i)!)^3, i=1..n): end:seq(2^ceil(n/2)*f(floor((n-1)/2))*f(floor(n/2)), n=1..20);
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CROSSREFS
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Sequence in context: A133892 A089709 A055512 this_sequence A152480 A001660 A014052
Adjacent sequences: A078970 A078971 A078972 this_sequence A078974 A078975 A078976
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KEYWORD
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nonn
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AUTHOR
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Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Jan 12 2003
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