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 A091448 #12 Jul 04 2021 22:11:03 %S A091448 19,28,29,52,53,54,67,70,85,86,88,103,106,107,108,124,125,126,127,129, %T A091448 149,151,153,172,173,174,175,176,178,179,199,201,202,204,206,207,229, %U A091448 232,233,234,236,237,259,261,262,263,265,267,268,292,293,294,295,296 %N A091448 Numbers k such that a1 > a2, where [a0,a1,a2,...] is the simple continued fraction of sqrt(k). %e A091448 sqrt(19) = [4;2,1,3,1,2,8,...], for which a1 = 2 > 1 = a2. %t A091448 Select[Range@300,Quiet[#[[1]]>#[[2]]&[Last@ContinuedFraction[Sqrt@#]]]&] (* _Giorgos Kalogeropoulos_, Jul 04 2021 *) %o A091448 (PARI) for(k=2,300,my(c=contfrac(sqrt(k)));if(#c>=3&&c[2]>c[3],print1(k,", "))) \\ _Hugo Pfoertner_, Jul 04 2021 %Y A091448 Cf. A000196, A091453. %K A091448 nonn %O A091448 1,1 %A A091448 _Clark Kimberling_, Jan 10 2004