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 A043715 #10 Jul 25 2023 15:23:46 %S A043715 1,2,3,4,5,6,7,8,9,10,11,13,26,39,52,65,78,91,104,117,130,143,145,146, %T A043715 147,148,149,150,151,152,153,154,155,157,168,169,171,172,173,174,175, %U A043715 176,177,178,179,180,181,182,184,185,186,187 %N A043715 Numbers whose base-12 representation has an odd number of runs. %t A043715 Select[Range[200],OddQ[Length[Split[IntegerDigits[#,12]]]]&] (* _Harvey P. Dale_, Jul 25 2023 *) %K A043715 nonn,base %O A043715 1,2 %A A043715 _Clark Kimberling_