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 A329811 #14 Nov 22 2019 16:25:30 %S A329811 1,2,3,5,4,9,11,12,13,14,15,6,17,8,19,21,31,23,51,32,57,18,91,52,7,35, %T A329811 16,71,41,53,25,72,111,112,131,45,34,151,61,74,152,73,54,37,29,121, %U A329811 123,58,132,134,153,47,141,56,171,81,92,1111,211,213,145,38,191 %N A329811 Lexicographically earliest sequence of distinct positive integers such that for any consecutive triple of digits, say (x, y, z), x+y is a multiple of z. %C A329811 This sequence is infinite as we can always extend it with a repunit not yet used. %C A329811 All terms are zeroless. %C A329811 113 is the first zeroless number that cannot appear in this sequence. %H A329811 Rémy Sigrist, <a href="/A329811/b329811.txt">Table of n, a(n) for n = 1..10000</a> %H A329811 Rémy Sigrist, <a href="/A329811/a329811.png">Colored scatterplot of the first 100000 terms</a> (where the color is function of the previous term mod 100) %H A329811 Rémy Sigrist, <a href="/A329811/a329811_1.gp.txt">PARI program for A329811</a> %H A329811 Rémy Sigrist, <a href="/A329811/a329811.txt">C# program for A329811</a> %e A329811 The first terms, alongside the corresponding (x, y, z), are: %e A329811 n a(n) x y z %e A329811 -- ---- - - - %e A329811 1 1 1 2 3 %e A329811 2 2 2 3 5 %e A329811 3 3 3 5 4 %e A329811 4 5 5 4 9 %e A329811 5 4 4 9 1 %e A329811 6 9 9 1 1 %e A329811 7 11 1 1 1 %e A329811 1 1 2 %e A329811 8 12 1 2 1 %e A329811 2 1 3 %e A329811 9 13 1 3 1 %e A329811 3 1 4 %e A329811 10 14 1 4 1 %e A329811 4 1 5 %e A329811 11 15 1 5 6 %e A329811 5 6 1 %o A329811 (PARI) See Links section. %o A329811 (C#) See Links section. %Y A329811 Cf. A002275, A052382, A085947. %K A329811 nonn,base %O A329811 1,2 %A A329811 _Eric Angelini_ and _Rémy Sigrist_, Nov 21 2019