%I #14 Sep 24 2018 16:53:14
%S 1,3,4,6,9,10,12,13,14,15,18,19,21,24,27,30,31,32,33,36,37,39,40,41,
%T 42,43,44,45,46,47,48,51,54,57,58,59,60,63,64,66,69,72,75,78,81,84,87,
%U 90,93,94,95,96,97,98,99,100,101,102,105,108,111,112,113,114,117,118,120
%N a(0) = 1; for n>0, a(n) is taken to be the smallest positive integer greater than a(n-1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is a multiple of 3".
%C Is this the same sequence as A115837? - _Andrew S. Plewe_, May 08 2007
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">Numerical analogues of Aronson's sequence</a>, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://arXiv.org/abs/math.NT/0305308">Numerical analogues of Aronson's sequence</a> (math.NT/0305308)
%H <a href="/index/Aa#aan">Index entries for sequences of the a(a(n)) = 2n family</a>
%F a(a(n)) = 3*(n+1).
%o (PARI) {a=1; m=[1]; for(n=1,67,print1(a,","); a=a+1; if(m[1]==n, while(a%3>0,a++); m=if(length(m)==1,[],vecextract(m,"2.."))); m=concat(m,a))}
%Y Cf. A003605, A079253, A080711, A080712.
%Y Cf. A079000, A003605, A079253, A080711, A080712.
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_, Mar 05 2003
%E More terms and PARI code from _Klaus Brockhaus_, Mar 06 2003