%I #10 Jul 02 2019 11:05:22
%S 1,2,1,2,3,4,1,3,4,2,3,4,1,3,4,2,5,6,7,8,1,5,6,7,8,2,5,6,7,8,1,5,6,7,
%T 8,2,3,6,5,8,7,4,1,3,6,5,8,7,4,2,3,6,5,8,7,4,1,3,6,5,8,7,4,2,9,10,11,
%U 12,13,14,15,16,1,9,10,11,12,13,14,15,16,2
%N Walk a rook along the square spiral numbered 1, 2, 3, ... (cf. A274640); a(n) = mex of earlier values the rook can move to.
%C Mex here means "smallest positive missing number".
%C Add 1 to the terms of A308896.
%Y Cf. A274640, A308896.
%K nonn
%O 1,2
%A _N. J. A. Sloane_, Jul 02 2019
%E More terms from _Rémy Sigrist_, Jul 02 2019
