OFFSET
1,1
COMMENTS
n=1 corresponds to the usual Fibonacci sequence, for which f(12) = 144 = 12^2, so a(1)=12.
REFERENCES
J. H. E. Cohn, On square Fibonacci numbers, J. London Math. Soc. 39 (1964), 537-540.
LINKS
T. D. Noe, Table of n, a(n) for n = 1..10000
EXAMPLE
a(6)=10 since f(10) = 361 = 19^2 for sequence starting f(1)=1, f(2)=6.
MATHEMATICA
squareQ[n_] := IntegerQ[Sqrt[n]]; nn = 100; Table[f = {1, n}; Do[AppendTo[f, f[[-1]] + f[[-2]]], {i, 3, nn}]; k = 2; While[k++; k <= nn && ! squareQ[f[[k]]]]; If[k > nn, k = 0]; k, {n, 100}] (* T. D. Noe, Jan 28 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Jan 27 2014
STATUS
approved