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Search: id:A079479
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| A079479 |
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Denominator of number J(n) arising in computation of second moment of A*_n lattice. |
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+0
2
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| 1, 12, 18, 32, 375, 648, 33614, 196608, 1594323, 625000, 14147686146, 35831808, 1792160394037, 94911683664, 1922167968750, 140737488355328, 8587269154529447379, 61004779879896, 10960773715569604371878, 384000000000000000, 123629392983875275287, 978545447174632740656
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OFFSET
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1,2
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REFERENCES
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J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 476.
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EXAMPLE
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0, 1/12, 5/18, 19/32, 389/375, 1045/648, 78077/33614, ...
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MAPLE
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J := proc(n) option remember; local i; if n <= 1 then 0 else (n!/(8*(n+1)*n^(n-2))) * add( n^k/k!, k=0..n) -n^2/(4*(n+1)) +(1/(n+1))*add( binomial(n, i)*(i/n)^i*( (n-i)/n)^(n-i-1)*J(i), i=1..n-1); fi; end;
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CROSSREFS
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Cf. A072526.
Sequence in context: A075281 A167597 A007371 this_sequence A162694 A124205 A133403
Adjacent sequences: A079476 A079477 A079478 this_sequence A079480 A079481 A079482
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KEYWORD
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nonn,frac
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com), Aug 02 2003
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