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 A331989 #15 Feb 22 2020 22:24:01 %S A331989 1,2,3,4,5,6,7,8,9,10,23,41,50,24,13,52,40,15,26,30,12,43,51,20,34,16, %T A331989 25,31,42,53,14,27,35,18,29,36,17,28,39,45,21,37,46,19,32,47,56,38,49, %U A331989 57,60,48,59,61,70,54,62,71,58,63,72,80,64,73,81,65,74,82,67,90,83,69,75,84,91,68,79,102,76,85 %N A331989 Lexicographically earliest sequence of distinct positive integers such that five successive digits are always distinct. %H A331989 Carole Dubois, <a href="/A331989/b331989.txt">Table of n, a(n) for n = 1..5000</a> %e A331989 The 5 digits 1, 0, 2, 3, 4 of a(10), a(11) and the 1st digit of a(12) are distinct; %e A331989 the 5 digits 0, 2, 3, 4, 1 of the 2nd digit of a(10), a(11) and a(12) are distinct; %e A331989 the 5 digits 2, 3, 4, 1, 5 of a(11), a(12) and the 1st digit of a(13) are distinct; %e A331989 the 5 digits 3, 4, 1, 5, 0 of the 2nd digit of a(11), a(12) and a(13) are distinct; %e A331989 the 5 digits 4, 1, 5, 0, 2 of a(12), a(13) and the 1st digit of a(14) are distinct, etc. %Y A331989 Cf. A331975 (a variant with 3 successive distinct digits), A331215 (a variant with 4 successive distinct digits). %K A331989 base,nonn %O A331989 1,2 %A A331989 _Eric Angelini_ and _Carole Dubois_, Feb 03 2020