hor = vector(10 000)
ver = vector(#hor)
dia = vector(2*#hor-1)

{
	for (d=1, #hor,
		for (c=1, d,
			r = d-c+1;
			x = bitor(hor[r], bitor(ver[c], dia[r-c+#hor]));
			v = valuation(1+x,2);
			p = 2^v;
			hor[r] += p;
			ver[c] += p;
			dia[r-c+#hor] += p;
			if (r==c,
				print (r-1 " " v);
			);
		);
	);
}

quit