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Search: id:A099529
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| A099529 |
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Expansion of (1+x)^2/((1+x)^2+x^3). |
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+0
3
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| 1, 0, 0, -1, 2, -3, 5, -9, 16, -28, 49, -86, 151, -265, 465, -816, 1432, -2513, 4410, -7739, 13581, -23833, 41824, -73396, 128801, -226030, 396655, -696081, 1221537, -2143648, 3761840, -6601569, 11584946, -20330163, 35676949, -62608681, 109870576, -192809420, 338356945, -593775046, 1042002567
(list; graph; listen)
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OFFSET
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0,5
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COMMENT
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Binomial transform has g.f. 1/(1-x+x^3) (A050935(n+2)).
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FORMULA
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a(n)=-2a(n-1)-a(n-2)-a(n-3); a(n)=sum{j=0..n, sum{k=0..floor(j/3), C(n, j)(-1)^(n-j)C(j-2k, k)(-1)^k}}.
a(n)=(-1)^n*A005314(n-2). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Nov 26 2008]
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CROSSREFS
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Sequence in context: A018160 A079960 A005314 this_sequence A088352 A002572 A114834
Adjacent sequences: A099526 A099527 A099528 this_sequence A099530 A099531 A099532
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KEYWORD
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easy,sign
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AUTHOR
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Paul Barry (pbarry(AT)wit.ie), Oct 20 2004
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