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%I #11 Feb 12 2023 10:05:34
%S 1,11,21,2,12,31,3,13,41,4,14,51,5,15,61,6,16,71,7,17,81,8,18,91,9,19,
%T 101,10,110,111,121,112,131,113,141,114,151,115,161,116,171,117,181,
%U 118,191,119,201,20,22,32,23,42,24,52,25,62,26,72,27,82,28,92
%N Lexicographically earliest sequence of distinct positive integers such that for any n > 0, the k rightmost digits of a(n+1) equal the k leftmost digits of a(n) for some k > 0.
%C Leading zeros are ignored.
%C This sequence is a permutation of the positive integers with inverse A360472:
%C - if a(n) < 10^e, then we can extend the sequence with a number of the form a(n) + k * 10^e (with k > 0),
%C - by the pigeonhole principle, there are infinitely many terms starting with the same nonzero digit, say with d,
%C - every number of the form 10*k + d (with k >= 0) appears in the sequence,
%C - any number v can appear after a term of the form v * 10^k + d (with k > 0).
%H Rémy Sigrist, <a href="/A360470/b360470.txt">Table of n, a(n) for n = 1..10000</a>
%H Rémy Sigrist, <a href="/A360470/a360470.png">Scatterplot of the first 1000000 terms</a>
%H Rémy Sigrist, <a href="/A360470/a360470.gp.txt">PARI program</a>
%H <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a>
%e The first terms are:
%e n a(n) a(n) aligned
%e -- ---- ------------
%e 1 1 1
%e 2 11 11
%e 3 21 21
%e 4 2 2
%e 5 12 12
%e 6 31 31
%e 7 3 3
%e 8 13 13
%e 9 41 41
%e 10 4 4
%e 11 14 14
%e 12 51 51
%o (PARI) See Links section.
%Y Cf. A262323, A360472 (inverse).
%K nonn,base
%O 1,2
%A _Rémy Sigrist_, Feb 08 2023
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