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 A368485 #36 Jan 15 2024 10:05:36 %S A368485 1,1,2,1,2,3,1,2,3,3,4,1,2,3,4,5,1,2,3,4,5,4,4,5,6,1,2,3,4,5,5,5,6,7, %T A368485 1,2,3,4,5,6,6,7,8,1,2,3,4,5,6,7,8,9,1,2,3,4,5,6,7,8,9,6,6,6,7,7,8,9, %U A368485 10,1,2,3,4,5,6,7,8,9,7,7,7,8,8,9,10,11 %N A368485 Lexicographically earliest infinite sequence of positive integers such that for n > 1, a(n - a(n)) is distinct for all indices n with the same a(n) value. %C A368485 Consider each index i as a location from which one can jump a(i) terms backwards. Any two distinct indices m and k, where a(m)=a(k), will jump to distinct values. In other words, every 1 will jump back to a distinct value, every 2, 3, etc. %H A368485 Rémy Sigrist, <a href="/A368485/b368485.txt">Table of n, a(n) for n = 1..10000</a> %H A368485 Rémy Sigrist, <a href="/A368485/a368485.gp.txt">PARI program</a> %e A368485 We can see, for example, that the values reached by jumping backwards once from each 3 in the sequence are all distinct: %e A368485 1, 1, 2, 1, 2, 3, 1, 2, 3, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3 %e A368485 2<=======* %e A368485 3<=======* %e A368485 1<=======* 4<=======* 5<=======* %o A368485 (PARI) See Links section. %Y A368485 Cf. A367849, A367832, A367467. %K A368485 nonn %O A368485 1,3 %A A368485 _Neal Gersh Tolunsky_, Dec 28 2023 %E A368485 More terms from _Rémy Sigrist_, Jan 15 2024