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A205505 Fibonacci(n*(n+1)) / Fibonacci(n). 1
1, 8, 72, 2255, 166408, 33489287, 17373187209, 23735905327584, 84707858657965180, 792123204706451722511, 19386236394149894806708656, 1242293991563772001787883943693, 208405704482555536994509895576090977, 91533085042008706066658193727853843719640 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..14.

FORMULA

a(n) = [x^n] 1/(1 - Lucas(n)*x + (-1)^n*x^2), where Lucas(n) = A000204(n).

Forms a diagonal in table A028412.

MATHEMATICA

Table[Fibonacci[n(n+1)]/Fibonacci[n], {n, 20}] (* Harvey P. Dale, Mar 30 2012 *)

PROG

(PARI) {a(n)=fibonacci(n*(n+1))/fibonacci(n)}

(PARI) {Lucas(n)=fibonacci(n-1)+fibonacci(n+1)}

{a(n)=polcoeff(1/(1-Lucas(n)*x+(-1)^n*x^2+x*O(x^n)), n)}

CROSSREFS

Cf. A103624, A051294, A028412.

Sequence in context: A242597 A241032 A001799 * A058068 A096873 A282786

Adjacent sequences:  A205502 A205503 A205504 * A205506 A205507 A205508

KEYWORD

nonn,easy

AUTHOR

Paul D. Hanna, Jan 28 2012

STATUS

approved

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Last modified August 14 08:08 EDT 2020. Contains 336480 sequences. (Running on oeis4.)