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A078973 Total dimension of the homology of a free 2-step nilpotent Lie algebra of rank n. 0
2, 6, 36, 420, 9800, 452760, 41835024, 7691667984, 2828336198688, 2073619375892064, 3040584296923128384, 8898500292240756664896, 52084270468105185237918848, 608812309050346291991694422400 (list; graph; refs; listen; history; internal format)
OFFSET

1,1

FORMULA

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.

MAPLE

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);

CROSSREFS

Sequence in context: A196870 A089709 A055512 * A152480 A001660 A014052

Adjacent sequences:  A078970 A078971 A078972 * A078974 A078975 A078976

KEYWORD

nonn

AUTHOR

Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Jan 12 2003

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Last modified February 17 11:46 EST 2012. Contains 206011 sequences.