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Search: id:A081009
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| A081009 |
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Fibonacci(4n+3)-1, or Fibonacci(2n+2)*Lucas(2n+1). |
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+0
1
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| 1, 12, 88, 609, 4180, 28656, 196417, 1346268, 9227464, 63245985, 433494436, 2971215072, 20365011073, 139583862444, 956722026040, 6557470319841, 44945570212852, 308061521170128, 2111485077978049, 14472334024676220
(list; graph; listen)
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OFFSET
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0,2
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REFERENCES
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Hugh C. Williams, Edouard Lucas and Primality Testing, John Wiley and Sons, 1998, p. 75
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FORMULA
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a(n) = 8a(n-1)-8a(n-2)+a(n-3)
a(n)=-1+[(7/2)-(3/2)*sqrt(5)]^n+[(7/2)+(3/2)*sqrt(5)]^n+(2/5)*sqrt(5)*{[(7/2)+(3/2)*sqrt(5)]^n -[(7/2)-(3/2)*sqrt(5)]^n}, with n>=0 [From Paolo P. Lava (ppl(AT)spl.at), Dec 01 2008]
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MAPLE
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with(combinat) for n from 0 to 25 do printf(`%d, `, fibonacci(4*n+3)-1) od
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CROSSREFS
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Cf. A000045 (Fibonacci numbers), A000032 (Lucas numbers).
Sequence in context: A057406 A125349 A164608 this_sequence A155635 A126507 A009657
Adjacent sequences: A081006 A081007 A081008 this_sequence A081010 A081011 A081012
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KEYWORD
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nonn,easy
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AUTHOR
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R. K. Guy (rkg(AT)cpsc.ucalgary.ca), Mar 01, 2003
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EXTENSIONS
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More terms and Maple code from James A. Sellers (sellersj(AT)math.psu.edu), Mar 03, 2003
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