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A128273
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a(n) = the denominator of b(n): {b(n)} is such that the continued fraction (of rational terms) [b(1);b(2),...,b(n)] equals the F(n+1)^2/F(n)^2, for every positive integer n, where F(n) is the n-th Fibonacci number.
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2
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1, 3, 7, 171, 2401, 419121, 39647713, 47740815747, 30877916418391, 255080753983140651, 1130395777976404261441, 177322193432863810849593, 1944244855966235024678049078337, 754657638581703992960984555289787011
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OFFSET
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1,2
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COMMENTS
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limit{n -> inf} b(n)*b(n+1) = 1.
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LINKS
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EXAMPLE
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b(n): 1, 1/3, 15/7, 77/171, 5301/2401,...
F(5)^2/F(4)^2 = 25/9 equals [b(1);b(2),b(3),b(4)] = 1 +1/(1/3 +1/(15/7 +171/77)).
F(6)^2/F(5)^2 = 64/25 equals [b(1);b(2),b(3),b(4),b(5)] = 1 +1/(1/3 +1/(15/7 +1/(77/171 +2401/5301)).
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MAPLE
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A128273 := proc(nmax) local a, b, i, n, ffrac ; b := [1] ; while nops(b) < nmax do n := nops(b)+1 ; ffrac := (combinat[fibonacci](n+1)/combinat[fibonacci](n))^2 ; for i from 1 to n-1 do ffrac := 1/(ffrac-b[i]) ; od: b := [op(b), ffrac] ; od: a := [] ; for i from 1 to nops(b) do a := [op(a), denom(op(i, b))] ; od: RETURN(a) ; end: op(A128273(17)) ; # R. J. Mathar, Oct 08 2007
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CROSSREFS
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KEYWORD
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frac,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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