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A009017
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E.g.f. cos(x*exp(x)).
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0
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1, 0, -1, -6, -23, -60, -1, 1526, 15121, 106344, 579359, 1870418, -8716487, -251210388, -3217413473, -31518844530, -245728084447, -1260370850736, 3075924210623, 208464730479658, 3846319817704841, 52691292058337940
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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FORMULA
| a(n):=sum(k=0..n/2, binomial(n,2*k)*(2*k)^(n-2*k)*(-1)^k), n>0, a(0)=1. [From Vladimir Kruchinin, Jun 29 2011]
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PROG
| (Maxima)
a(n):=if n=0 then 1 else sum(binomial(n, 2*k)*(2*k)^(n-2*k)*(-1)^k, k, 0, n/2); [From Vladimir Kruchinin, Jun 29 2011]
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CROSSREFS
| Sequence in context: A026817 A189713 A162267 * A119712 A005745 A045618
Adjacent sequences: A009014 A009015 A009016 * A009018 A009019 A009020
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KEYWORD
| sign,easy
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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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