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 A032883 #9 Feb 12 2021 21:36:24
%S A032883 1,2,3,4,8,9,12,13,14,24,25,28,29,30,44,45,46,68,72,73,76,77,78,132,
%T A032883 136,137,140,141,142,152,153,156,157,158,196,200,201,204,205,206,216,
%U A032883 217,220,221,222,236,237,238,388,392,393,396,397
%N A032883 Numbers whose base-4 representation Sum_{i=0..m} d(i)*4^i has d(0) < d(1) > d(2) < ...
%K A032883 nonn,base
%O A032883 1,2
%A A032883 _Clark Kimberling_