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A015451
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a(n) = 6 a(n-1) + a(n-2).
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5
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1, 1, 7, 43, 265, 1633, 10063, 62011, 382129, 2354785, 14510839, 89419819, 551029753, 3395598337, 20924619775, 128943316987, 794584521697, 4896450447169, 30173287204711, 185936173675435, 1145790329257321
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,3
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COMMENTS
| a(n) = term (1,1) in the 2x2 matrix [1,2; 3,5]^n. - Gary W. Adamson (qntmpkt(AT)yahoo.com), May 30 2008
a(n)/a(n-1) tends to sqrt(10 + 3 = 6.16227766... - Gary W. Adamson (qntmpkt(AT)yahoo.com), May 30 2008
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LINKS
| Tanya Khovanova, Recursive Sequences
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FORMULA
| a(n)=Sum_{k, 0<=k<=n}5^k*A055830(n,k) . - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Oct 18 2006
a(n)=(1/10)*[3-sqrt(10)]^n*sqrt(10)-(1/10)*[3+sqrt(10)]^n*sqrt(10)+(1/2)*[3+sqrt(10)]^n+(1/2) *[3-sqrt(10)]^n, with n>=0 - Paolo P. Lava (paoloplava(AT)gmail.com), Jun 25 2008
G.f.: (1-5*x)/(1-6*x-x^2). [From Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Nov 20 2008]
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MAPLE
| a[0]:=1: a[1]:=1: for n from 2 to 26 do a[n]:=6*a[n-1]+a[n-2] od: seq(a[n], n=0..20); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Jul 26 2006
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CROSSREFS
| Sequence in context: A161728 A003464 A022036 * A194779 A126502 A199483
Adjacent sequences: A015448 A015449 A015450 * A015452 A015453 A015454
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KEYWORD
| nonn,easy
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AUTHOR
| Olivier Gerard (olivier.gerard(AT)gmail.com)
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