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 A093103 a(1)=1, a(2)=8, a(n+2) = 8*a(n+1) + 21*a(n). 2
 1, 8, 85, 848, 8569, 86360, 870829, 8780192, 88528945, 892615592, 9000032581, 90745188080, 914962188841, 9225346460408, 93016977648925, 937868096859968, 9456301305507169, 95345640478116680, 961347451240583989 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,2 COMMENTS a(n+1)/a(n) converges to 4+sqrt(37). LINKS Index entries for linear recurrences with constant coefficients, signature (8, 21). FORMULA a(n)=(1/2)*[4-sqrt(37)]^n+(2/37)*sqrt(37)*[4+sqrt(37)]^n+(1/2)*[4+sqrt(37)]^n-(2/37)*[4 -sqrt(37)]^n*sqrt(37), with n>=0 - Paolo P. Lava, Jul 08 2008 G.f.: x/(1-8x-21x^2). [From R. J. Mathar, Nov 30 2008] MATHEMATICA Join[{b=1}, a=0; Table[c=8*b+21*a; a=b; b=c, {n, 30}]] (* Vladimir Joseph Stephan Orlovsky, Apr 22 2011 *) LinearRecurrence[{8, 21}, {1, 8}, 20] (* Harvey P. Dale, Jan 14 2012 *) CROSSREFS Cf. A093117, A094703. Sequence in context: A281340 A298283 A299176 * A288691 A300675 A241323 Adjacent sequences: A093100 A093101 A093102 * A093104 A093105 A093106 KEYWORD nonn AUTHOR Gary W. Adamson, May 20 2004 EXTENSIONS More terms from Robert G. Wilson v, May 24 2004 Edited by Don Reble, Nov 04 2005 STATUS approved

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Last modified December 5 21:40 EST 2022. Contains 358594 sequences. (Running on oeis4.)