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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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1
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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; refs; listen; history; internal format)
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OFFSET
| 2,1
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COMMENTS
| 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
| 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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MATHEMATICA
| Rest[Table[n!Sum[(-1)^(i+1)/i, {i, n-1}], {n, 20}]] (* From Harvey P. Dale, Oct 24 2011 *)
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PROG
| (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
| Cf. A024167, A052881.
Sequence in context: A055814 A151370 A041567 * A007113 A066166 A052804
Adjacent sequences: A087298 A087299 A087300 * A087302 A087303 A087304
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KEYWORD
| nonn
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AUTHOR
| Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 20 2003
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