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 A009203 Expansion of exp(sin(tan(x))). 3
 1, 1, 1, 2, 5, 8, 13, -232, -2199, -25600, -218311, -2258048, -20057555, -212565376, -1933691003, -21159275264, -181405779887, -1935285600256, -10159446470927, -49976214294528, 2835996855537109, 63805712413261824 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,4 LINKS Vladimir Kruchinin, D. V. Kruchinin, Composita and their properties , arXiv:1103.2582 FORMULA a(n):=sum(sum(if oddp(n+k) or oddp(k-m) then 0 else (-1)^((n+k)/2)*sum(j!*stirling2(n,j)*2^(n-j)*(-1)^(n+j-k)*binomial(j-1,k-1),j,k,n)*2^(1-m)*sum((-1)^(floor((k+m)/2)-i)*binomial(m,i)*(2*i-m)^k/k!/m!,i,0,floor(m/2)) ,k,m,n),m,1,n), n>0. - Vladimir Kruchinin, Sep 01 2010 MATHEMATICA With[{nn=30}, CoefficientList[Series[Exp[Sin[Tan[x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Oct 13 2018 *) PROG (Maxima) a(n):=sum(sum(if oddp(n+k) or oddp(k-m) then 0 else (-1)^((n+k)/2)*sum(j!*stirling2(n, j)*2^(n-j)*(-1)^(n+j-k)*binomial(j-1, k-1), j, k, n)*2^(1-m)*sum((-1)^(floor((k+m)/2)-i)*binomial(m, i)*(2*i-m)^k/k!/m!, i, 0, floor(m/2)) , k, m, n), m, 1, n); /* Vladimir Kruchinin, Sep 01 2010 */ CROSSREFS Sequence in context: A200275 A075731 A009238 * A202273 A210702 A173177 Adjacent sequences:  A009200 A009201 A009202 * A009204 A009205 A009206 KEYWORD sign,easy AUTHOR EXTENSIONS Extended with signs by Olivier Gérard, Mar 15 1997 Prior Mathematica program replaced by Harvey P. Dale, Oct 13 2018 STATUS approved

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Last modified January 28 06:29 EST 2020. Contains 331317 sequences. (Running on oeis4.)