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A058937
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Maximal exponent of x in all terms of Somos polynomial of order n.
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2
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1, 0, 0, 0, 0, 1, 2, 3, 5, 7, 9, 12, 15, 18, 22, 26, 30, 35, 40, 45, 51, 57, 63, 70, 77, 84, 92, 100, 108, 117, 126, 135, 145, 155, 165, 176, 187, 198, 210, 222, 234, 247, 260, 273, 287, 301, 315, 330, 345, 360, 376, 392, 408, 425, 442, 459, 477, 495, 513, 532, 551
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,7
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COMMENTS
| This sequence differs from A001840 only in four terms preceding it.
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LINKS
| M. Somos, Somos Polynomials
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FORMULA
| e(n) = 1 + e(n-1) + e(n-3) - e(n-4).
G.f.: x*(1-2*x+x^2-x^3+2*x^4)/((1+x+x^2)* (1-x)^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 27 2009]
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MATHEMATICA
| e[1] = 1; e[2] = e[3] = e[4] = e[5] = 0; e[n_] := e[n] = 1 + e[n - 1] + e[n - 3] - e[n - 4]; Table[e[n], {n, 1, 70}]
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PROG
| (Other) sage: [floor(binomial(n, 2)/3) for n in xrange(-2, 59)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Dec 01 2009]
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CROSSREFS
| Cf. A001840.
Sequence in context: A071423 A062781 A145919 * A130518 A001840 A022794
Adjacent sequences: A058934 A058935 A058936 * A058938 A058939 A058940
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com), Jan 11 2001
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EXTENSIONS
| G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.
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