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Search: id:A081076
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| A081076 |
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Lucas(4n)+3, or 5*Fibonacci(2n-1)*Fibonacci(2n+1). |
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+0
1
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| 5, 10, 50, 325, 2210, 15130, 103685, 710650, 4870850, 33385285, 228826130, 1568397610, 10749957125, 73681302250, 505019158610, 3461452808005, 23725150497410, 162614600673850, 1114577054219525, 7639424778862810
(list; graph; listen)
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OFFSET
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0,1
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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)=3+[(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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luc := proc(n) option remember: if n=0 then RETURN(2) fi: if n=1 then RETURN(1) fi: luc(n-1)+luc(n-2): end: for n from 0 to 40 do printf(`%d, `, luc(4*n)+3) od:
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CROSSREFS
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Cf. A000045 (Fibonacci numbers), A000032 (Lucas numbers).
Sequence in context: A034190 A003587 A032088 this_sequence A005438 A072309 A061518
Adjacent sequences: A081073 A081074 A081075 this_sequence A081077 A081078 A081079
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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 04, 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 05, 2003
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