Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #16 May 26 2019 11:30:53
%S 1,2,3,4,5,6,7,8,9,110,111,100,112,113,114,115,101,102,116,117,120,
%T 118,119,130,210,211,140,212,213,150,214,103,215,216,104,121,217,218,
%U 160,219,310,170,311,122,105,312,313,180,314,315,190,316,131,106,123,317
%N Lexicographically earliest sequence of distinct terms such that reading one-by-one the central digit of each term is the same as reading one-by-one the successive digits of the sequence itself.
%C All terms of the sequence have an odd number of digits. For terms having only an even number of digits, see the Cross-references section.
%H Lars Blomberg, <a href="/A308406/b308406.txt">Table of n, a(n) for n = 1..10000</a>
%e The "central digit" of 1 is 1, of course. The central digit of 100 is 0, the central digit of 123 is 2, etc. Reading the successive central digits of the successive terms produces 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 1, 0, 1, 1, 1, 1, 0, 0, sequence, which are exactly the successive digits of the sequence itself.
%Y Cf. A308407 (the same idea, but with terms having an even number of digits).
%K base,nonn
%O 1,2
%A _Eric Angelini_, May 25 2019
%E More terms from _Lars Blomberg_, May 26 2019