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Search: id:A087301
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| A087301 |
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a(n) = n!*Sum_{i=1..n-1} (-1)^(i+1)/i. |
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+0
2
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| 2, 3, 20, 70, 564, 3108, 30624, 230256, 2705760, 25771680, 352805760, 4067556480, 63651813120, 861371884800, 15176802816000, 235775183616000, 4620563523072000, 81032645804544000, 1748700390205440000
(list; graph; listen)
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OFFSET
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2,1
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COMMENT
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Stirling transform of A052882(n)=[0,2,9,52,375,...] is a(n+1)=[0,2,3,20,...]. - Michael Somos Mar 04 2004
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FORMULA
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E.g.f.: x*ln(1+x)/(1-x). a(n) = 1/2*(-1)^n*n!*(2*(-1)^n*ln(2)+Psi(1/2+1/2*n)-Psi(1/2*n)).
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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))*x/(1-x), n))
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CROSSREFS
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Cf. A024167, A052881.
Sequence in context: A072472 A055814 A041567 this_sequence A007113 A066166 A052804
Adjacent sequences: A087298 A087299 A087300 this_sequence A087302 A087303 A087304
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KEYWORD
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nonn
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AUTHOR
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Vladeta Jovovic (vladeta(AT)Eunet.yu), Oct 20 2003
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