%I
%S 0,2,4,1,6,7,8,10,12,11,14,16,18,15,20,22,24,19,26,28,30,23,32,34,36,
%T 27,38,40,42,31,44,46,48,35,50,52,54,39,56,58,60,43,62,64,66,47,68,70,
%U 72,51,74,76,78,55,80,82,84,59,86,88,90,63,92,94,96,67,98,100,102,71,104
%N a(n) is taken to be the smallest positive integer not already present which is consistent with the condition "n is a member of the sequence if and only if a(n) is even".
%C The same sequence, but without the initial 0, obeis the rule: "The concatenation of a(n) and a(a(n)) is even". Example: "2" and the 2nd term, concatenated, is 24; "4" and the 4th term, concatenated, is 46; "1" and the 1st term, concatenated, is 12; etc.  _Eric Angelini_, Feb 22 2017
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/VOL6/Cloitre/cloitre2.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>, arXiv:math/0305308 [math.NT], 2003.
%F For n >= 4 a(n) is given by: a(4m)=6m, a(4m+1)=4m+3, a(4m+2)=6m+2, a(4m+3)=6m+4.
%Y Cf. A079000, A080029, A080030. Equals A079313  1.
%K easy,nonn
%O 0,2
%A _N. J. A. Sloane_, Mar 14 2003
%E More terms from _Matthew Vandermast_, Mar 21 2003
