%I M0409
%S 0,1,2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,
%T 2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,2,3,1,4,3,2,0,5,2,3,
%U 1,4,3,2,0,5,2,3,1,4,3,2,0,5,2
%N The game of contours.
%D E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982, see p. 553.
%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%F a(0) = 0, b(1) = 0, a(n) = mex({a(s) ^ b(t): s+t = n1 and s>0} union {b(s) + b(t): s+t = n1}), b(n) = mex({a(s) ^ b(t): s+t = n1 and s>0}) with ^ denoting bitwise addition.  _Sean A. Irvine_, Dec 14 2016
%F a(n+8) = a(n) for n >= 6.  _Sean A. Irvine_, Dec 14 2016
%K nonn
%O 0,3
%A _N. J. A. Sloane_.
%E More terms from _Sean A. Irvine_, Dec 14 2016
