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Search: id:A008990
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| A008990 |
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Numerators of sequence having sqrt(cos x) as e.g.f. |
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+0
1
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| 1, -1, -1, -19, -559, -29161, -2368081, -276580459, -43947282079, -9118829535121, -2394495729300961, -776228170682260099, -304471093666800990799, -142128398853646068197881, -77865168574139358455774641, -49474260304294496117945326939
(list; graph; listen)
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OFFSET
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0,4
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REFERENCES
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R. P. Stanley, Enumerative Combinatorics, Cambridge, Vol. 2, 1999; see page 191.
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FORMULA
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E.g.f.: sqrt(cos(sqrt(2)*x)) = 1 - x^2/2! - x^4/4! - 19x^6/6! -... - Ralf Stephan, Mar 03 2005
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CROSSREFS
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Sequence in context: A158211 A035278 A092611 this_sequence A012845 A142023 A075879
Adjacent sequences: A008987 A008988 A008989 this_sequence A008991 A008992 A008993
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KEYWORD
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sign,easy,nice
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AUTHOR
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N. J. A. Sloane (njas(AT)research.att.com).
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