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 A362093 #12 Apr 09 2023 21:52:22 %S A362093 1,2,3,4,5,6,7,8,9,20,22,10,30,11,23,33,24,12,34,13,35,14,36,15,37,16, %T A362093 38,17,39,18,40,19,43,31,44,25,26,27,28,29,32,21,42,45,41,50,46,51,47, %U A362093 52,48,53,49,55,54,56,57,58,59,60,62,61,63,64,65,66,67,68,69,70,72,71,73,74,75,76,77 %N A362093 a(1) = 1, a(2) = 2; for n > 2, a(n) is the least positive integer not occurring earlier such that a(n) shares no digit with a(n-1) - a(n-2). %C A362093 The sequence is likely to be finite although it contains at least 1 million terms. %C A362093 Sequence is finite with 6080472 terms, since a(6080471) = 660606060 and a(6080472) = 8822811 have difference -651783249. - _Michael S. Branicky_, Apr 09 2023 %H A362093 Michael S. Branicky, <a href="/A362093/a362093.py.txt">Python program</a> %H A362093 Scott R. Shannon, <a href="/A362093/a362093.png">Image of the first 1 million terms</a>. The green line is a(n) = n. %e A362093 a(11) = 22 as a(10) - a(9) = 20 - 9 = 11, and 22 is the smallest unused number that does not contain the digit 1. %o A362093 (Python) # see link for program that generates full sequence %Y A362093 Cf. A362075, A362076, A342441, A342442, A067581, A297065. %K A362093 nonn %O A362093 1,2 %A A362093 _Scott R. Shannon_, Apr 08 2023