%I A122005
%S A122005 1,2,3,1,4,5,6,2,7,8,9,3,1,10,11,12,4,13,14,15,5,16,17,18,6,2,19,20,21,
%T A122005 7,22,23,24,8,25,26,27,9,3,1,28,29,30,10,31,32,33,11,34,35,36,12,4,37,
%U A122005 38,39,13,40,41,42,14,43,44,45,15,5,46,47,48,12,4,49,50,51,17
%N A122005 Triangle read by rows: n-th row starts with n and continues with 1/3 
               the previous value as long as that is an integer.
%C A122005 A fractal sequence, which is to 3 as A123390 is to 2. Row lengths are 
               A051064 3^a(n) exactly divides 3n. Or, 3-adic valuation of 3n.
%F A122005 a(1) = 1, for n > 1, if 3|a(n-1) then a(n) = a(n-1)/3, otherwise a(n) 
               = (max_{k<n} a(k)) + 1.
%Y A122005 Cf. A051064, A123390.
%Y A122005 Sequence in context: A055449 A055442 A055439 this_sequence A117385 A071517 
               A046671
%Y A122005 Adjacent sequences: A122002 A122003 A122004 this_sequence A122006 A122007 
               A122008
%K A122005 easy,nonn,tabf
%O A122005 1,2
%A A122005 Jonathan Vos Post (jvospost3(AT)gmail.com), Oct 14 2006