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A009486
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sin(sin(x)*sin(x)) = 2/2!*x^2-8/4!*x^4-88/6!*x^6+6592/8!*x^8...
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2
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0, 2, -8, -88, 6592, -251488, 4158592, 551599232, -94759774208, 9549823734272, -506903275563008, -67623197282080768, 30434079688615739392, -6806476994628810661888, 994937886379415577198592
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,2
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FORMULA
| a(n) = 1/2*sum(k=0..(n-1)/2,(4^(n-2*k)*sum(i=0..2*k+1, (i-2*k-1)^(2*n)*binomial(4*k+2,i)*(-1)^(n-i+k-1)))/(2*k+1)!). [From Vladimir Kruchinin, Jun 28 2011]
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MATHEMATICA
| Sin[ Sin[ x ]^2 ] (* Even Part *)
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PROG
| (Maxima)
a(n):=1/2*sum((4^(n-2*k)*sum((i-2*k-1)^(2*n)*binomial(4*k+2, i)*(-1)^(n-i+k-1), i, 0, 2*k+1))/(2*k+1)!, k, 0, (n-1)/2); [From Vladimir Kruchinin, Jun 28 2011]
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CROSSREFS
| Sequence in context: A054955 A012299 A012295 * A110384 A153887 A131349
Adjacent sequences: A009483 A009484 A009485 * A009487 A009488 A009489
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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.
Edited by N. J. A. Sloane (njas(AT)research.att.com), May 31 2008 at the suggestion of R. J. Mathar
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