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Search: id:A092692
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| A092692 |
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Expansion of -log(1-x)/(1-x^2). |
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+0
2
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| 0, 1, 1, 8, 18, 184, 660, 8448, 42000, 648576, 4142880, 74972160, 586776960, 12174658560, 113020427520, 2643856588800, 28432576972800, 740051782041600, 9056055981772800, 259500083163955200, 3562946373482496000
(list; graph; listen)
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OFFSET
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0,4
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COMMENT
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Stirling transform of (-1)^n*a(n-1)=[0,1,-1,8,-18,...] is A052882(n-1)=[0,1,2,9,52,...].
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FORMULA
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E.g.f.: -log(1-x)/(1-x^2).
a(n) = n!*Sum_{k=1..n} (-1)^(n-k)*Harmonic(k). - Vladeta Jovovic (vladeta(AT)Eunet.yu), Aug 14 2005
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PROGRAM
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(PARI) a(n)=if(n<0, 0, n!*polcoeff(-log(1-x+x*O(x^n))/(1-x^2), n))
(PARI) {a(n)=if(n<0, 0, n!*sum(k=1, n, ((n-k+1)%2)/k))} /* Michael Somos Sep 19 2006 */
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CROSSREFS
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Adjacent sequences: A092689 A092690 A092691 this_sequence A092693 A092694 A092695
Sequence in context: A120543 A036747 A113563 this_sequence A001151 A138492 A022512
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KEYWORD
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nonn
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AUTHOR
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Michael Somos, Mar 04 2004
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