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 A050023 #10 Jul 04 2021 13:43:30 %S A050023 2,3,6,7,8,9,10,11,13,14,16,17,18,19,23,24,25,26,27,28,29,31,32,33,34, %T A050023 35,37,38,39,41,42,43,45,46,47,49,53,54,55,56,57,58,59,60,61,62,63,65, %U A050023 66,67,68,70,71,73,74,75,76,77,80,81,82,83 %N A050023 Numbers k such that A050020(k) > A050020(k+1). %K A050023 nonn,easy %O A050023 1,1 %A A050023 _Clark Kimberling_