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 A233423 #8 Dec 12 2015 16:48:23
%S A233423 1,2,3,6,7,13,19,21,22,31,43,46,76,94,124,133,139,151,166,211,214,244,
%T A233423 301,309,331,421,526,571,604,631,751,886,919,991,1279,1291,1324,1366,
%U A233423 1516,1621,1726,2011,2311,2566,2671,3004,3019,3259,3334,3691,3931,4174
%N A233423 Values of n at which the period of the continued fraction for sqrt(n) is nondecreasing.
%t A233423 t = {1}; mx = 0; n = 1; While[Length[t] < 60, n++; If[! IntegerQ[Sqrt[n]], len = Length[ContinuedFraction[Sqrt[n]][[2]]]; If[len >= mx, AppendTo[t, n]; mx = len]]]; t (* _T. D. Noe_, Dec 10 2013 *)
%Y A233423 Superset of A013645.
%K A233423 nonn
%O A233423 1,2
%A A233423 _David Spies_, Dec 09 2013
%E A233423 Extended by _T. D. Noe_, Dec 10 2013