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 A357030 #56 Mar 04 2024 08:51:20
%S A357030 1,2,3,4,5,6,7,8,9,10,11,12,12,12,12,12,12,12,12,12,13,14,15,15,15,15,
%T A357030 15,15,15,15,16,17,18,19,19,19,19,19,19,19,20,21,22,23,24,24,24,24,24,
%U A357030 24,25,26,27,28,29,30,30,30,30,30,31,32,33,34,35,36,37,37,37,37,38,39,40
%N A357030 a(n) is the number of integers in 0..n having nonincreasing digits.
%e A357030 a(20) = 13 because there are 13 numbers in 0..20 whose digits are in nonincreasing order: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 20.
%p A357030 a:= proc(n) option remember; `if`(n<0, 0, a(n-1)+`if`(
%p A357030 (l-> is(l=sort(l)))(convert(n, base, 10)), 1, 0))
%p A357030 end:
%p A357030 seq(a(n), n=0..72); # _Alois P. Heinz_, Sep 12 2022
%t A357030 Accumulate @ Table[If[GreaterEqual @@ IntegerDigits[n], 1, 0], {n, 0, 72}] (* _Amiram Eldar_, Sep 10 2022 *)
%o A357030 (PARI) a(n) = sum(k=0, n, my(d=digits(k)); d == vecsort(d,,4)); \\ _Michel Marcus_, Sep 10 2022
%Y A357030 Cf. A009996.
%K A357030 nonn,base
%O A357030 0,2
%A A357030 _Osman Mustafa Quddusi_, Sep 09 2022