%I #10 Jan 05 2021 14:42:50
%S 0,1,2,3,4,5,6,7,8,9,19,29,39,49,59,69,79,89,99,90,10,20,30,40,50,60,
%T 70,80,81,11,21,31,41,51,61,71,91,92,12,22,32,42,52,62,72,82,83,13,23,
%U 33,43,53,63,73,93,94,14,24,34,44,54,64,74,84,85,15,25,35
%N Lexicographically earliest sequence of distinct nonnegative terms such that for any n >= 0, a(n+1) is obtained by altering the leftmost decimal digit (which is not a leading zero) in a(n) or if this is not possible by altering the rightmost leading zero in a(n).
%C This sequence appears to be a permutation of the nonnegative integers.
%H Rémy Sigrist, <a href="/A340254/b340254.txt">Table of n, a(n) for n = 0..9999</a>
%H Rémy Sigrist, <a href="/A340254/a340254.gp.txt">PARI program for A340254</a>
%o (PARI) See Links section.
%Y See A340250 for similar sequences.
%K nonn,base
%O 0,3
%A _Rémy Sigrist_, Jan 02 2021