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A009546
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Expansion of sin(x)*sin(sin(x)).
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1
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0, 2, -12, 118, -1816, 37354, -974372, 31769182, -1259350576, 59073098706, -3226127944764, 202778723085382, -14503292667068744, 1168138817072817594, -105070093531389641300, 10481640556778901446190, -1152522131016352310551648
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n) = 2*sum(k=1..n, (4^(n-k)*sum(i=0..k, (i-k)^(2*n)*binomial(2*k,i)*(-1)^(n-i-1)))/(2*k-1)!). [From Vladimir Kruchinin, Jun 28 2011]
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MATHEMATICA
| Sin[ x ]*Sin[ Sin[ x ] ] (* Even Part *)
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PROG
| (Maxima)
a(n):=2*sum((4^(n-k)*sum((i-k)^(2*n)*binomial(2*k, i)*(-1)^(n-i-1), i, 0, k))/(2*k-1)!, k, 1, n); [From Vladimir Kruchinin, Jun 28 2011]
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CROSSREFS
| Sequence in context: A009742 A121425 A132692 * A009748 A095717 A089431
Adjacent sequences: A009543 A009544 A009545 * A009547 A009548 A009549
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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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