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A009777
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E.g.f. tanh(log(1+x))*cosh(x).
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0
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0, 1, -1, 3, 0, -25, 165, -623, 392, 18909, -206685, 1233551, -1161336, -81119597, 1241356025, -10102782675, 12681799920, 1158387845177, -22791296600793, 234950313889819, -368659923645520, -41597707520306049
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,4
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LINKS
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FORMULA
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a(n)=(sum(i=0..(n-1)/2, binomial(n,2*i)*(sum(m=1..n-2*i, (sum(k=1..m, (-1)^(k+1)*k!*2^(m-k)*stirling2(m,k)))*stirling1(n-2*i,m))))). - Vladimir Kruchinin, Jun 29 2011
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PROG
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(Maxima)
a(n):=(sum(binomial(n, 2*i)*(sum((sum((-1)^(k+1)*k!*2^(m-k)*stirling2(m, k), k, 1, m))*stirling1(n-2*i, m), m, 1, n-2*i)), i, 0, (n-1)/2)); /* Vladimir Kruchinin, Jun 29 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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STATUS
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approved
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