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 A329173 #14 Jun 04 2021 12:30:32 %S A329173 1,1,2,1,2,2,1,3,1,2,3,1,2,4,1,2,3,2,1,3,2,1,4,1,2,3,3,1,2,4,2,1,3,3, %T A329173 1,3,1,3,2,2,2,3,1,3,3,2,1,4,2,1,3,4,1,2,3,4,1,2,4,1,3,1,4,1,2,4,2,2, %U A329173 3,2,2,3,3,2,2,4,1,2,4,3,1,2,4,3,2,1,4 %N A329173 Smallest positive integer such that for any n no substring (subsequence without internal skips) of length n is repeated unless it contains the number n or higher. %H A329173 André Engels, <a href="/A329173/b329173.txt">Table of n, a(n) for n = 1..10000</a> %e A329173 After 1,1,2,1,2, the next element is 2, because a 1 would repeat the length 3 substring 1,2,1. A 2 repeats the length 2 substring 2,2, but that's allowed because it contains a 2. %K A329173 nonn %O A329173 1,3 %A A329173 _André Engels_, Nov 07 2019