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A271421
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Fibonorial(3*n)/(fibonorial(2*n+1)*fibonorial(n+1)), where fibonorial(n) = A003266(n).
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0
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1, 4, 119, 23496, 32149806, 300214157831, 19246160432331107, 8451529006578585976752, 25443734373070679510011112460, 524973397889459587964008354031908560, 74243674067972394056586805754940632245000310, 71965837912588688126721254257169744333502564695515911
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OFFSET
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1,2
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REFERENCES
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S. R. Finch, Mathematical Constants, Cambridge, 2003, Section 1.2.5.
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LINKS
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Table of n, a(n) for n=1..12.
Simon Plouffe, Fibonacci factorials.
Eric Weisstein's World of Mathematics, Fibonorial, Fibonacci Factorial Constant.
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FORMULA
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a(n) ~ 5*phi^(2*n^2 - 3*n - 2)/C where phi = (1+sqrt(5))/2, and C = (-1/phi^2; -1/phi^2)_inf is the Fibonacci factorial constant whose decimal expansion is given in A062073.
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MATHEMATICA
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Table[Fibonorial[3 n]/(Fibonorial[2 n + 1] Fibonorial[n + 1]), {n, 1, 30}] (* The sequence itself *)
QPochhammer[-1/GoldenRatio^2] (* The Fibonacci factorial constant C in the asymptotic expansion *)
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CROSSREFS
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Cf. A003266, A003267, A003268, A062073, A003150, A000045.
Sequence in context: A264420 A283035 A284764 * A064204 A054644 A006434
Adjacent sequences: A271418 A271419 A271420 * A271422 A271423 A271424
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KEYWORD
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nonn,easy
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AUTHOR
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Vladimir Reshetnikov, May 21 2016
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STATUS
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approved
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