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 A032901 #13 Jan 29 2019 09:20:13
%S A032901 1,2,3,4,5,8,9,10,12,13,14,15,20,21,24,25,26,28,29,30,31,40,41,42,44,
%T A032901 45,46,47,60,61,62,63,64,68,69,72,73,74,76,77,78,79,84,85,88,89,90,92,
%U A032901 93,94,95,128,132,133,136,137,138,140,141,142
%N A032901 Numbers whose base-4 representation Sum_{i=0..m} d(i)*4^i has d(0) <= d(1) >= d(2) <= ...
%Y A032901 Cf. A032842, A032851, A032867, A032875, A032883, A032892.
%K A032901 nonn,base
%O A032901 1,2
%A A032901 _Clark Kimberling_, corrected Jul 07 2000