big = 1 000 000
s = 0
S = Set([])
unseen = 0
seen(v) = if (v < big, bit test(s, v), set search(S, v))
see(v) = if (v < big, s = bit or(s, 2^v), S = set union(S, Set([v]))); while (seen(unseen), unseen++)

tr(n) = if (n>0, 2*n, 1-2*n)

row = vector(1+2*M=50)
col = vector(#row)

move(z) = {
	my (w=max(abs(real(z)), abs(imag(z))));
	if (imag(z)==-w, z+1,
		real(z)==-w, z-I,
		imag(z)==+w, z-1,
	                 z+I);
}

\\ i-th number with no bit in common with x
avoid(x,i) = {
	if (x==0 || i==0, i,
	    x%2, 2*avoid(x\2, i),
		     2*avoid(x\2, i\2)+i%2)
}

{
	n=-1;
	z=0;

	while (max(abs(x=real(z)), abs(y=imag(z)))<=M,
		prv = bitor(col[tr(x)], row[tr(y)]);
		for (i=0, oo,
			if (!seen(v=avoid(prv,i)) && bitand(prv, v)==0,
				print (n++ " " v);

				see(v);
				col[tr(x)] += v;
				row[tr(y)] += v;

				break;
			);
		);

		z=move(z);
	);
}

quit