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 A043684 #7 Apr 13 2021 23:07:32 %S A043684 85,149,165,169,170,171,173,181,213,277,293,297,298,299,301,309,325, %T A043684 329,330,331,333,337,338,339,340,342,343,345,346,347,349,357,361,362, %U A043684 363,365,373,405,421,425,426,427,429,437,469,533 %N A043684 a(n) = (1/2)*(n-th number whose base-2 representation has exactly 8 runs). %K A043684 nonn,base %O A043684 1,1 %A A043684 _Clark Kimberling_