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 A050019 #10 Jul 04 2021 13:41:54 %S A050019 2,3,6,7,8,9,10,12,13,15,16,17,18,19,21,23,24,25,26,28,29,31,32,33,34, %T A050019 36,39,40,41,42,43,45,46,47,48,49,51,52,53,55,57,58,59,60,61,62,64,65, %U A050019 66,68,69,70,72,73,74,76,78,79,80,81,83,84 %N A050019 Numbers k such that A050016(k) > A050016(k+1). %K A050019 nonn,easy %O A050019 1,1 %A A050019 _Clark Kimberling_