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A009362
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Expansion of log(1 + sinh(x)/exp(x)).
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2
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0, 1, -3, 12, -66, 480, -4368, 47712, -608016, 8855040, -145083648, 2641216512, -52891055616, 1155444326400, -27344999497728, 696933753434112, -19031293222127616, 554336947975618560, -17155693983744196608
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OFFSET
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0,3
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LINKS
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FORMULA
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a(n) = -Sum_{k>0} (-2*k)^n/3^k/k = -(-2)^n*polylog(-n+1, 1/3), n>0. - Vladeta Jovovic, Sep 30 2003
a(n) = -(-1)^n*Sum_{k=0..n-1} 3^k*Sum_{j=0..k} (-1)^j*(k-j)^n*C(n,j) for n>0. a(n) = -(-1)^n*Sum_{k=0..n-1} 3^k*A008292(n-1,k) for n>0, where A008292 are the Eulerian numbers. - Paul D. Hanna, Mar 29 2006
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MATHEMATICA
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Log[ 1+Sinh[ x ]/Exp[ x ] ]
CoefficientList[Series[Log[1 + Sinh[x]/E^x], {x, 0, 20}], x] * Range[0, 20]! (* Vaclav Kotesovec, Jan 23 2015 *)
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PROG
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(PARI) a(n)=-(-1)^n*sum(k=0, n-1, 3^k*sum(j=0, k, (-1)^j*(k-j)^(n-1)*binomial(n, j))) \\ Paul D. Hanna, Mar 29 2006
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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