%I #3 Mar 31 2012 13:46:51
%S 1,11,12,21,22,24,28,31,32,36,38,41,42,48,52,61,62,71,72,74,78,85,94,
%T 96,114,124,128,129,131,132,136,137,138,141,142,148,152,153,154,162,
%U 163,164,172,173
%N Slowest increasing sequence where: 1) a(n) cannot contain any "0" and 2) a(n) must contain one digit of the product of the digits of a(n-1).
%e After a(n)=1 we cannot have 10 (presence of a "0"), thus 11; product of 1x1 is 1, so next integer must contain a "1", thus 12; product 1x2=2, so next integer must contain a "2", thus 21 (20 not allowed), etc.
%K base,easy,nonn
%O 1,2
%A _Eric Angelini_, Jun 09 2005