login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A113500
Maximum element in the continued fraction for F(5n+3)^5/F(5n+2)^5 where F=A000045 are Fibonacci numbers.
3
32, 3042, 375131, 46137317, 5674515856, 697919312217, 85838400887831, 10557425389890242, 1298477484555612931, 159702173174950499517, 19642068823034355828656, 2415814763060050816424417
OFFSET
0,1
REFERENCES
B. Cloitre, On rational sequences yielding continued fractions with unbounded coefficients, in preparation
FORMULA
a(n) = 2*L(10*n+4) + L(10*n+5) + (-1)^n*7 - 1, where L(k) denotes the k-th Lucas number L(k) = F(k-1) + F(k+1), for n >= 0.
Empirical g.f.: (x^4-140*x^3-965*x^2+894*x-32) / ((x-1)*(x+1)*(x^2-123*x+1)). - Colin Barker, Jun 17 2013
MATHEMATICA
Table[2*LucasL[10*n + 4] + LucasL[10*n + 5] + 7*(-1)^n - 1, {n, 0, 50}] (* G. C. Greubel, Mar 13 2017 *)
PROG
(PARI) a(n)=vecmax(contfrac(fibonacci(5*n+3)^5/fibonacci(5*n+2)^5))
CROSSREFS
Cf. A000045.
Sequence in context: A248074 A220299 A264115 * A064018 A067321 A104652
KEYWORD
nonn
AUTHOR
Benoit Cloitre, Jan 10 2006
STATUS
approved