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A009798
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E.g.f. tanh(sin(x)*cos(x)) (odd powers only).
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1
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1, -6, 112, -5488, 451840, -57057792, 10262228992, -2484525168640, 779280513040384, -307370299649556480, 148889329569589362688, -86890528715348714192896, 60129120979379216762011648
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OFFSET
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0,2
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LINKS
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FORMULA
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a(n):=(-1)^n*sum(k=0..n, 4^(n-k)/(2*k+1)!*sum(i=0..2*k+1, (-1)^i*(2*k+1-2*i)^(2*n+1)*binomial(2*k+1, i))*(sum(j=1..2*k+1, j!*2^(-j)*(-1)^(k+1+j)*stirling2(2*k+1, j)))). - Vladimir Kruchinin, Jun 29 2011
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PROG
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(Maxima)
a(n):=(-1)^n*sum(4^(n-k)/(2*k+1)!*sum((-1)^i*(2*k+1-2*i)^(2*n+1)*binomial(2*k+1, i), i, 0, 2*k+1)*(sum(j!*2^(-j)*(-1)^(k+1+j)*stirling2(2*k+1, j), j, 1, 2*k+1)), k, 0, n); /* Vladimir Kruchinin, Jun 28 2011 */
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CROSSREFS
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KEYWORD
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sign
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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