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 A043708 #8 Jun 18 2021 23:04:29 %S A043708 1,2,3,4,6,12,18,24,26,27,28,29,31,35,36,38,39,40,41,42,44,45,46,47, %T A043708 48,51,52,53,54,55,57,58,59,62,65,66,67,69,70,71,72,73,76,77,78,79,80, %U A043708 82,83,84,85,86,88,89,93,95,96,97,98,101 %N A043708 Numbers whose base-5 representation has an odd number of runs. %K A043708 nonn,base %O A043708 1,2 %A A043708 _Clark Kimberling_