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A002969
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E.g.f. 1/(1-sin(x)+sin(x)^2).
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0
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1, 1, 0, -7, -24, 61, 1200, 4493, -48384, -781319, -1804800, 85444193, 1210361856, -1847527499, -288162201600, -3428482320907, 33720680349696, 1637781983297521, 14158399925452800, -431041350297034807, -14236987086964260864
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,4
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FORMULA
| a(n)=2*sum(m=1..n, sum(j=0..(n-m)/2, (binomial(m,n-m-2*j)*sum(i=0..(n-2*j)/2, (2*i+2*j-n)^n*binomial(n-2*j,i)*(-1)^(m-j-i)))/2^(n-2*j))), n>0, a(0)=1. [From Vladimir Kruchinin, Jun 08 2011]
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PROG
| (Maxima)
a(n):=2*sum(sum((binomial(m, n-m-2*j)*sum((2*i+2*j-n)^n*binomial(n-2*j, i)*(-1)^(m-j-i), i, 0, (n-2*j)/2))/2^(n-2*j), j, 0, (n-m)/2), m, 1, n); [From Vladimir Kruchinin, Jun 08 2011]
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CROSSREFS
| Cf. A029585.
Sequence in context: A062449 A014205 A029585 * A114291 A101903 A196349
Adjacent sequences: A002966 A002967 A002968 * A002970 A002971 A002972
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KEYWORD
| sign
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AUTHOR
| N. J. A. Sloane (njas(AT)research.att.com).
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