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A106540
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a(n)= a(n-1)-2*a(n-2)-3*a(n-3)-...-(n-1)*a(1), beginning with 1.
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1
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1, 1, -1, -6, -11, -5, 28, 87, 111, -46, -519, -1105, -812, 2051, 8003, 12130, 477, -43213, -107764, -106273, 133575, 716562, 1269265, 492135, -3436796, -10232533, -12529349, 6701026, 62284757, 128290443, 86849596, -256333913, -946668833
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,4
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COMMENTS
| To accommodate the first three terms, the conjectured generating function must be changed to -1/2+(1/2)*(1-x+x^2)/(1-3x+5x^2-2x^3). [From R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 22 2008]
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FORMULA
| G.f.: (2*x^2 - 3*x - 1)/(-2*x^3 + 5*x^2 - 3*x + 1) (conjectured).
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EXAMPLE
| a(5)=-6-2*(-1)-3*1-4*1=-6+2-3-4=-11
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CROSSREFS
| Sequence in context: A115677 A100129 A009443 * A134012 A103704 A135998
Adjacent sequences: A106537 A106538 A106539 * A106541 A106542 A106543
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KEYWORD
| easy,sign
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AUTHOR
| Alexandre Wajnberg (alexandre.wajnberg(AT)ulb.ac.be), May 08 2005
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EXTENSIONS
| Extended beyond a(14) by R. J. Mathar (mathar(AT)strw.leidenuniv.nl), Aug 22 2008
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