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A009050
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E.g.f. cos(x*sin(x)) (even power only).
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0
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1, 0, -12, 120, 784, -95040, 3292608, -9423232, -9230042880, 890079012864, -40083887897600, -2468650419873792, 837675174905843712, -109581967679961088000, 5834566862721760149504
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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FORMULA
| a(n)=2*sum(k=1..n-1, binomial(2*n,2*k)*(4^(n-2*k)*(-1)^(k)*sum(i=0..k-1, (i-k)^(2*n-2*k)*binomial(2*k,i)*(-1)^(n-i)))), n>0, a(0)=1. [From Vladimir Kruchinin, Jun 30 2011]
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PROG
| (Maxima)
a(n):=if n=0 then 1 else 2*sum(binomial(2*n, 2*k)*(4^(n-2*k)*(-1)^(k)*sum((i-k)^(2*n-2*k)*binomial(2*k, i)*(-1)^(n-i), i, 0, k-1)), k, 1, n-1); [From Vladimir Kruchinin, Jun 30 2011]
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CROSSREFS
| Sequence in context: A133386 A056320 A056311 * A067358 A061506 A059155
Adjacent sequences: A009047 A009048 A009049 * A009051 A009052 A009053
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KEYWORD
| sign
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AUTHOR
| R. H. Hardin (rhhardin(AT)att.net)
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EXTENSIONS
| Extended with signs Mar 15 1997 by Olivier Gerard.
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