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Search: id:A007655
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| 0, 1, 14, 195, 2716, 37829, 526890, 7338631, 102213944, 1423656585, 19828978246, 276182038859, 3846719565780, 53577891882061, 746243766783074, 10393834843080975, 144767444036350576
(list; graph; listen)
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OFFSET
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1,3
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COMMENT
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a(n)=A001353(2n)/4. a(n) corresponds also to one-sixth the area of Fleenor-Heronian triangle with middle side A003500(n). - Lekraj Beedassy (blekraj(AT)yahoo.com), Jul 15 2002
a(n) give all (nontrivial, integer) solutions of Pell equation b(n+1)^2 - 48*a(n+1)^2 = +1 with b(n+1)=A011943(n), n>=0.
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REFERENCES
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D. A. Benaron, personal communication.
E. K. Lloyd (E.K.Lloyd(AT)maths.soton.ac.uk), "The standard deviation of 1, 2, .., n, Pell's equation and rational triangles", preprint.
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LINKS
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T. D. Noe, Table of n, a(n) for n=1..100
Tanya Khovanova, Recursive Sequences
Index entries for sequences related to Chebyshev polynomials.
Zerinvary Lajos, Sage Notebooks
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FORMULA
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a(n) = 14*a(n-1) - a(n-2). G.f.: (x^2)/(1-14*x+x^2).
a(n+1) ~ 1/24*sqrt(3)*(2 + sqrt(3))^(2*n) - Joe Keane (jgk(AT)jgk.org), May 15 2002
a(n+1) = S(n-1, 14), n>=0, with S(n, x) := U(n, x/2) Chebyshev's polynomials of the second kind. S(-1, x) := 0. See A049310.
a(n+1) = ((7+4*sqrt(3))^n - (7-4*sqrt(3))^n)/(8*sqrt(3)).
a(n+1) = sqrt((A011943(n)^2 - 1)/48), n>=0.
Chebyshev's polynomials U(n-2, x) evaluated at x=7.
4*a(n+1) + A046184(n) = A055793(n+2) + A098301(n+1) 4*a(n+1) + A098301(n+1) + A055793(n+2) = A046184(n+1) (4*a(n+1))^2 = A098301(2n+1) (conjectures) - Creighton Dement (creighton.k.dement(AT)uni-oldenburg.de), Nov 02 2004
(4*a(n))^2 = A103974(n)^2 - A011922(n-1)^2. - Paul D. Hanna (pauldhanna(AT)juno.com), Mar 06 2005
a(n) = 13*(a(n-1)+a(n-2))-a(n-3), a(n) = 15*(a(n-1)-a(n-2))+a(n-3). a(n)=14*a(n-1)-a(n-2). - Mohamed Bouhamida (bhmd95(AT)yahoo.fr), May 26 2007
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PROGRAM
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sage: [lucas_number1(n, 14, 1) for n in xrange(0, 20)] - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jun 25 2008
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CROSSREFS
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Cf. A001353, A003500.
Cf. A011945, A067900.
Cf. A103974, A011922.
Sequence in context: A091030 A055759 A086946 this_sequence A001023 A067221 A072533
Adjacent sequences: A007652 A007653 A007654 this_sequence A007656 A007657 A007658
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KEYWORD
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nonn,easy
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AUTHOR
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njas
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EXTENSIONS
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Chebyshev comments from W. Lang (wolfdieter.lang(AT)physik.uni-karlsruhe.de), Nov 08 2002
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