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A007116
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Expansion of e.g.f. (1+x)^(exp(x)).
(Formerly M1634)
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3
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1, 1, 2, 6, 18, 75, 295, 1575, 7196, 48993, 230413, 2164767, 8055938, 139431149, 70125991, 14201296057, -77573062280, 2389977322593, -28817693086263, 615493949444827, -10403976760589602, 215611836994976237
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OFFSET
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0,3
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REFERENCES
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N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
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LINKS
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FORMULA
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a(n) = sum(k=1..n, sum(i=0..n-k, binomial(n,i)*k^i*Stirling1(n-i,k))), n>0, a(0)=1. - Vladimir Kruchinin, Jun 01 2011
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MATHEMATICA
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With[{nn=25}, CoefficientList[Series[(1+x)^Exp[x], {x, 0, nn}], x] Range[ 0, nn]!] (* Harvey P. Dale, Sep 21 2011 *)
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PROG
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(Maxima)
a(n):=sum(sum(binomial(n, i)*k^i*stirling1(n-i, k), i, 0, n-k), k, 1, n); /* Vladimir Kruchinin, Jun 01 2011 */
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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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Definition and terms corrected, and more terms added by Joerg Arndt, Jun 01 2011
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STATUS
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approved
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