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Search: id:A133479
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| A133479 |
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a(n)=a(n-1)+8*a(n-2) for n>=2, a(0)=1, a(1)=2 . |
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+0
1
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| 1, 2, 10, 26, 106, 314, 1162, 3674, 12970, 42362, 146122, 485018, 1653994, 5534138, 18766090, 63039194, 213167914, 717481466, 2422824778, 8162676506, 27545274730, 92846686778, 313208884618, 1055982378842, 3561653455786
(list; graph; listen)
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OFFSET
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0,2
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FORMULA
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G.f.: (1+x)/(1-x-8*x^2) .
a(n)=Sum_{k, 0<=k<=n+1}A122950(n+1,k)*7^(n+1-k). - Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 08 2008
a(n)=-(1/22)*[(1/2)-(1/2)*sqrt(33)]^n*sqrt(33)+(1/2)*[(1/2)-(1/2)*sqrt(33)]^n+(1/22)*sqrt(33)*[(1/2) +(1/2)*sqrt(33)]^n+(1/2)*[(1/2)+(1/2)*sqrt(33)]^n, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Nov 18 2008]
a(n)= ((11+sqrt(33))/22)*(0.5+0.5*sqrt(33))^n+((11-sqrt(33))/22)*(0.5-0.5*sqrt(33))^n [From Richard Choulet (richardchoulet(AT)yahoo.fr), Nov 20 2008]
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CROSSREFS
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Sequence in context: A025589 A084182 A099583 this_sequence A057753 A060515 A109723
Adjacent sequences: A133476 A133477 A133478 this_sequence A133480 A133481 A133482
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KEYWORD
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easy,nonn,new
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AUTHOR
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Philippe DELEHAM (kolotoko(AT)wanadoo.fr), Jan 03 2008
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