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 A318486 #5 Aug 27 2018 08:15:33 %S A318486 1,10,2,11,3,12,4,13,5,14,6,15,7,16,8,17,9,18,70,40,71,50,60,51,72,61, %T A318486 62,73,74,80,30,81,41,82,52,83,63,84,75,90,20,91,31,92,42,93,53,94,64, %U A318486 95,78,19,85,86,96,89,100,101,23,102,34,103,24,25,35,26,45,104,36,37,46,27,56,105,47,38,57,28,67,106,58,39 %N A318486 Lexicographically first sequence of different positive terms such that a(n) - [the first digit of a(n+1)] is a palindrome. %H A318486 Jean-Marc Falcoz, <a href="/A318486/b318486.txt">Table of n, a(n) for n = 1..10001</a> %e A318486 The sequence starts with 1,10,2,11,3,12,4,13,5,14,6… and we see that [1 - (the first digit of 10 = 1)] is a palindrome (0); [10 - (the first digit of 2 = 2)] is a palindrome (8); [2 - (the first digit of 11 = 1)] is a palindrome (1); [11 - (the first digit of 3 = 3)] is a palindrome (8); etc. %K A318486 base,nonn,look %O A318486 1,2 %A A318486 _Eric Angelini_ and _Jean-Marc Falcoz_, Aug 27 2018