This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A064850 #15 Feb 10 2016 13:45:50
%S A064850 1,2,6,2,5,4,10,4,2,14,12,4,5,10,28,8,1,2,4,14,6,8,6,4,31,14,10,12,12,
%T A064850 20,8,20,20,2,52,2,19,4,28,24,18,8,50,12,28,6,10,4,70,62,8,18,7,10,6,
%U A064850 8,8,12,72,20,3,12,8,36,41,28,86,2,6,44,84,2,43,42,120,4,52,36,28,44,38
%N A064850 Period of continued fraction for sqrt(5)*n.
%e A064850 A040002 (cfrac for n=1) has period length 1, so a(1)=1. A040015 (cfrac for n=2) has period length 2, so a(2)=2. A010135 (cfrac for n=3) has period length 6, so a(3)=6. - _R. J. Mathar_, Feb 10 2016
%t A064850 Table[Length[ContinuedFraction[Sqrt[5]n][[2]]],{n,90}] (* _Harvey P. Dale_, Apr 13 2015 *)
%K A064850 nonn
%O A064850 1,2
%A A064850 _R. K. Guy_, Oct 26 2001