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 A004177 #17 Sep 16 2024 09:22:50
%S A004177 0,1,0,3,4,5,6,7,8,9,10,11,1,13,14,15,16,17,18,19,0,1,0,3,4,5,6,7,8,9,
%T A004177 30,31,3,33,34,35,36,37,38,39,40,41,4,43,44,45,46,47,48,49,50,51,5,53,
%U A004177 54,55,56,57,58,59,60,61,6,63,64,65,66,67,68,69,70,71,7,73,74
%N A004177 Omit 2's from n.
%H A004177 Robert Israel, <a href="/A004177/b004177.txt">Table of n, a(n) for n = 0..10000</a>
%p A004177 f:= proc(n) local L,i;
%p A004177 L:= subs(2=NULL,convert(n,base,10));
%p A004177 add(L[i]*10^(i-1),i=1..nops(L))
%p A004177 end proc:
%p A004177 map(f, [$0..100]); # _Robert Israel_, Sep 15 2024
%t A004177 Table[FromDigits[DeleteCases[IntegerDigits[n],2]],{n,0,80}] (* _Harvey P. Dale_, Feb 12 2022 *)
%Y A004177 Cf. A004176, A004178, A004179, A004180, A004181, A004182, A004183, A004184.
%Y A004177 Cf. A004719.
%K A004177 nonn,base,look
%O A004177 0,4
%A A004177 _N. J. A. Sloane_