%I #16 Mar 23 2017 14:33:25
%S 1,2,3,4,6,5,7,8,9,12,10,11,20,14,16,13,18,19,15,21,40,41,44,22,23,24,
%T 46,48,49,17,25,26,60,61,64,66,27,28,68,69,80,81,84,42,29,86,88,89,90,
%U 43,30,91,94,96,98,99,31,100,101,104,106,108,109,45,32,33,34,110,111,114,116,47,35,36,118,119,140,141,144,37,38,146
%N The nonprime digits in the sequence appear in blocks and the successive sizes of these blocks are given by the sequence itself.
%C The sequence is started with a(1)=1 and always extended with the smallest integer not yet present that does not lead to a contradiction.
%H Eric Angelini, <a href="/A275659/b275659.txt">Table of n, a(n) for n = 1..1001</a>
%e The blocks of nonprime digits are indicated hereunder by parentheses; the successive block-sizes are 1, 2, 3, 4, 6, 5, ... which reproduces the sequence itself: (1),2,3,(4,6),5,7,(8,9,1)2,(10,11),2(0,14,16,1)3,(18,19,1)5,...
%K nonn,base
%O 1,2
%A _Eric Angelini_ and _Lars Blomberg_, Aug 04 2016