login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A271421 Fibonorial(3*n)/(fibonorial(2*n+1)*fibonorial(n+1)), where fibonorial(n) = A003266(n). 0
1, 4, 119, 23496, 32149806, 300214157831, 19246160432331107, 8451529006578585976752, 25443734373070679510011112460, 524973397889459587964008354031908560, 74243674067972394056586805754940632245000310, 71965837912588688126721254257169744333502564695515911 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

S. R. Finch, Mathematical Constants, Cambridge, 2003, Section 1.2.5.

LINKS

Table of n, a(n) for n=1..12.

Simon Plouffe, Fibonacci factorials.

Eric Weisstein's World of Mathematics, Fibonorial, Fibonacci Factorial Constant.

FORMULA

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.

MATHEMATICA

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 *)

CROSSREFS

Cf. A003266, A003267, A003268, A062073, A003150, A000045.

Sequence in context: A264420 A283035 A284764 * A064204 A054644 A006434

Adjacent sequences:  A271418 A271419 A271420 * A271422 A271423 A271424

KEYWORD

nonn,easy

AUTHOR

Vladimir Reshetnikov, May 21 2016

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent | More pages
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 16 06:50 EST 2018. Contains 317258 sequences. (Running on oeis4.)