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 A043657 #11 Aug 29 2025 16:17:59 %S A043657 13,15,16,17,18,19,20,21,22,23,24,25,26,27,29,30,31,32,33,34,35,36,37, %T A043657 38,39,40,41,43,44,45,46,47,48,49,50,51,52,53,54,55,57,58,59,60,61,62, %U A043657 63,64,65,66,67,68,69,71,72,73,74,75,76,77 %N A043657 Numbers whose base-13 representation has exactly 2 runs. %Y A043657 Subsequence of A043702. %K A043657 nonn,base,changed %O A043657 1,1 %A A043657 _Clark Kimberling_