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 A260264 #19 Dec 23 2024 14:53:44
%S A260264 0,9,17,26,35,44,53,62,71,80,89,96,104,113,122,131,140,149,157,166,
%T A260264 175,184,193,201,210,219,227,236,245,254,263,272,281,290,298,305,314,
%U A260264 323,332,341,350,359,367,376,385,394,402,411,420,429,437,446,455,464,473,482
%N A260264 a(n+1) = a(n) + largest digit not in a(n), starting with a(0) = 0.
%C A260264 From a(16173532) = 123456798 on, the sequence becomes constant.
%C A260264 From a(324) = 2798 + 6 = 2804 on, this sequence becomes equal to sequence A260263, which has the same definition except for starting with a(1) = 1.
%C A260264 a(10^k) = 9, 89, 874, 8598, 84284, 823330, 8010205, 77737463, 123456798, ...
%H A260264 M. F. Hasler, <a href="/A260264/b260264.txt">Table of n, a(n) for n = 0..1000</a>
%H A260264 E. Angelini, <a href="https://web.archive.org/web/*/http://list.seqfan.eu/oldermail/seqfan/2015-July/015110.html">Add the biggest absent digit</a>, SeqFan list, Jul 21, 2015
%t A260264 NestList[#+Max[Complement[Range[0,9],IntegerDigits[#]]]&,0,60] (* _Harvey P. Dale_, May 17 2019 *)
%o A260264 (PARI) {L=0;a=0;d=vector(9,d,d);for(n=0,1000,n>=L&&print1(a",")+L*=10;a+=vecmax(setminus(d,Set(digits(a)))))} \\ Set L=1 to list only a(10^k).
%Y A260264 Cf. A045844.
%K A260264 nonn,base
%O A260264 0,2
%A A260264 _Eric Angelini_ and _M. F. Hasler_, Jul 21 2015