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 A087301 a(n) = n!*Sum_{i=1..n-1} (-1)^(i+1)/i. 1
 2, 3, 20, 70, 564, 3108, 30624, 230256, 2705760, 25771680, 352805760, 4067556480, 63651813120, 861371884800, 15176802816000, 235775183616000, 4620563523072000, 81032645804544000, 1748700390205440000 (list; graph; refs; listen; history; text; internal format)
 OFFSET 2,1 COMMENTS Stirling transform of A052882(n)=[0,2,9,52,375,...] is a(n+1)=[0,2,3,20,...]. - Michael Somos, Mar 04 2004 LINKS Table of n, a(n) for n=2..20. FORMULA E.g.f.: x*log(1+x)/(1-x). a(n) = 1/2*(-1)^n*n!*(2*(-1)^n*log(2)+Psi(1/2+1/2*n)-Psi(1/2*n)). a(n) ~ n! * log(2). - Vaclav Kotesovec, Jul 01 2018 MATHEMATICA Rest[Table[n!Sum[(-1)^(i+1)/i, {i, n-1}], {n, 20}]] (* Harvey P. Dale, Oct 24 2011 *) PROG (PARI) a(n)=if(n<0, 0, n!*polcoeff(log(1+x+x*O(x^n))*x/(1-x), n)) CROSSREFS Cf. A024167, A052881. Sequence in context: A151370 A041567 A338084 * A292122 A264417 A348311 Adjacent sequences: A087298 A087299 A087300 * A087302 A087303 A087304 KEYWORD nonn AUTHOR Vladeta Jovovic, Oct 20 2003 STATUS approved

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Last modified May 18 18:37 EDT 2024. Contains 372664 sequences. (Running on oeis4.)