%I A141842
%S A141842 18,86,680,835,7087,12788,18478,128117,385732,2206280,13176873,33185141,
%T A141842 68388408,335213686,1365888758
%N A141842 a(n) = first term that can be reduced in n steps via repeated interpretation 
               of a(n) as a base b+1 number where b is the largest digit of a(n), 
               such that b is always 8 so that each interpretation is base 9. Terms 
               already fully reduced (i.e. single digits) are excluded.
%C A141842 It is sometimes possible to compute additional terms by taking the last 
               term, treating it as base 10 and converting to base 9. This may create 
               a term minimally interprettable as base 9 which can converted back 
               to base 10 yielding the previous term in the sequence which will 
               itself yield N further terms. But there is no guarantee (except in 
               base 2) that the term so derived will be the first term to produce 
               a sequence of N+1 terms. There could be another, smaller, term which 
               satisfies that requirement but which uses different terms. Pushing 
               the last term of this sequence does not produce a value minimally 
               interprettable as base 9.
%e A141842 a(3) = 680 because 680 is the first number that can produce a sequence 
               of three terms by repeated interpetation as a base 9 number: [680] 
               (base-9) --> [558] (base-9) --> [458] (base-9) --> [377]. Since 377 
               cannot be minimally interpretted as a base 9 number, the sequence 
               terminates with 458. a(1) = 18 because 18 is the first number that 
               can be reduced once, yielding no further terms minimally interprettable 
               as base 9.
%Y A141842 Cf. A091049, A141836, A141837, A141838, A141839, A141840, A141841.
%Y A141842 Sequence in context: A067984 A124935 A126405 this_sequence A063788 A066854 
               A059138
%Y A141842 Adjacent sequences: A141839 A141840 A141841 this_sequence A141843 A141844 
               A141845
%K A141842 base,more,nonn
%O A141842 1,1
%A A141842 Chuck Seggelin (seqfan(AT)plastereddragon.com), Jul 10 2008