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 A043683 #7 Apr 13 2021 23:10:54 %S A043683 21,37,41,42,43,45,53,69,73,74,75,77,81,82,83,84,86,87,89,90,91,93, %T A043683 101,105,106,107,109,117,133,137,138,139,141,145,146,147,148,150,151, %U A043683 153,154,155,157,161,162,163,164,166,167,168,172 %N A043683 a(n) = (1/2)*(n-th number whose base-2 representation has exactly 6 runs). %K A043683 nonn,base %O A043683 1,1 %A A043683 _Clark Kimberling_