A103624 Quotient F(n(n+1))/{F(n)*F(n+1)}, where F(n) is the n-th Fibonacci number A000045(n).

1, 4, 24, 451, 20801, 2576099, 827294629, 698114862576, 1540142884690276, 8900260727038783399, 134626641626040936157699, 5331733869372412024840703621, 552800277142057127306392295957801

Offset

1,2

Links

Robert Israel, Table of n, a(n) for n = 1..69

Formula

a(n) = phi^(n^2 - n - 1) + O(phi^(n^2 - 3n)). [Charles R Greathouse IV, Feb 01 2012]

Maple

seq(combinat:-fibonacci(n*(n+1))/combinat:-fibonacci(n)/combinat:-fibonacci(n+1), n=1..25); # Robert Israel, Jan 11 2018

Mathematica

Table[Fibonacci[n(n+1)]/(Fibonacci[n]Fibonacci[n+1]), {n, 20}] (* Harvey P. Dale, Aug 04 2012 *)

Prog

(PARI) {a(n)=fibonacci(n*(n+1))/(fibonacci(n)*fibonacci(n+1))}  \\ Paul D. Hanna, Jan 28 2012

Crossrefs

Cf. A000045, A205505, A051294, A028412, A037943.

Sequence in context: A012945 A296398 A166947 * A101952 A009535 A139096

Adjacent sequences: A103621 A103622 A103623 * A103625 A103626 A103627

Keyword

nonn,easy

Author

Lekraj Beedassy, Mar 25 2005

Extensions

a(2) corrected by Paul D. Hanna, Jan 28 2012

Status

approved