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Search: id:A072263
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| A072263 |
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a(n) = 3 a(n-1) + 5 a(n-2). |
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+0
1
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| 3, 19, 72, 311, 1293, 5434, 22767, 95471, 400248, 1678099, 7035537, 29497106, 123669003, 518492539, 2173822632
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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If b(n)=A015523, a(n)=5*b(n-1)+b(n+1); b(n) is Fibonacci-type, a(n) is Lucas-type.
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FORMULA
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a(n)=[(3+sqrt(29))/2 ]^n + [ (3-sqrt(29))/2 ]^n.
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EXAMPLE
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a(5)=5*b(4)+b(6): 1293=5*57+1008
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PROGRAM
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(Other) sage: [lucas_number2(n, 3, -5) for n in xrange(1, 16)]# [From Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), Apr 30 2009]
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CROSSREFS
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Cf. A015523.
Sequence in context: A064056 A059599 A095662 this_sequence A090698 A027175 A093734
Adjacent sequences: A072260 A072261 A072262 this_sequence A072264 A072265 A072266
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KEYWORD
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easy,nonn
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AUTHOR
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M. Kristof (kristmikl(AT)freemail.hu), Jul 08 2002
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