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 A032902 #17 Jan 29 2019 09:22:36
%S A032902 1,2,3,4,5,6,10,11,12,15,16,17,18,20,21,22,23,24,30,31,35,36,37,40,41,
%T A032902 42,43,45,46,47,48,49,60,61,62,65,66,67,68,70,71,72,73,74,90,91,92,93,
%U A032902 95,96,97,98,99,120,121,122,123,124,125,130
%N A032902 Numbers whose base-5 representation Sum_{i=0..m} d(i)*5^i has d(0) <= d(1) >= d(2) <= ...
%o A032902 (PARI) is(n) = my(d = digits(n, 5), t=1, i); forstep(i=#d, 2, -1, if(d[i] * t > d[i-1] * t, return(0)); t=-t); 1 \\ _David A. Corneth_, Jan 29 2019
%Y A032902 Cf. A032852, A032860, A032868, A032876, A032884, A032893.
%K A032902 nonn,base
%O A032902 1,2
%A A032902 _Clark Kimberling_, corrected Jul 07 2000