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A141577
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Alternating difference recursion: a(0) = -1; a(1) = 0; a(2) = 1; a(3) = -1; a(n) = a(n-1) - 3*a(n-2) + 3*a(n-3) - a(n-4).
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0
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-1, 0, 1, -1, -3, 3, 8, -9, -21, 27, 55, -80, -143, 235, 369, -685, -944, 1983, 2391, -5705, -5985, 16320, 14769, -46441, -35803, 131507, 84824, -370665, -194813, 1040147, 427767, -2906448, -874495, 8088003, 1564377, -22416669, -1971296, 61883839, -1016657, -170165393, 20507391, 466069760
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OFFSET
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0,5
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REFERENCES
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Martin Gardner, Mathematical Circus, Random House, New York, 1981, p. 165.
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LINKS
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FORMULA
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O.g.f.: (-1+x-2x^2+x^3)/(1-x+3x^2-3x^3+x^4). - R. J. Mathar, Aug 25 2008
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PROG
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(PARI) x='x+O('x^99); Vec((1-x+2*x^2-x^3)/(-1+x-3*x^2+3*x^3-x^4)) \\ Altug Alkan, Dec 17 2017
For MATLAB, see
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CROSSREFS
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KEYWORD
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sign,easy
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AUTHOR
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Matt Wynne (mattwyn(AT)verizon.net), Aug 18 2008
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EXTENSIONS
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STATUS
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approved
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