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 A206583 #4 Mar 30 2012 17:23:03
%S A206583 2,11,28,335,69,1507,268,1963,589,7675,1318,2899,1549,11575,1789,
%T A206583 17371,3331,22459,3319,23791,6211,18019,6379,63379,6694,17131,9199,
%U A206583 75331,10189,49471,10429,75091,16069,105991,17509,114559,14221,152707,25141,159031,20959
%N A206583 The least number s having exactly n threes in the continued fraction of sqrt(s).
%t A206583 nn = 50; zeros = nn; t = Table[0, {nn}]; k = 2; While[zeros > 0, If[! IntegerQ[Sqrt[k]], cnt = Count[ContinuedFraction[Sqrt[k]][[2]], 3]; If[cnt <= nn && t[[cnt]] == 0, t[[cnt]] = k; zeros--]]; k++]; Join[{2}, t]
%Y A206583 Cf. A206578 (n ones), A206582 (n twos), A206584 (n fours), A206585 (n fives).
%K A206583 nonn
%O A206583 0,1
%A A206583 _T. D. Noe_, Mar 19 2012