{
	n = 0;

	print (n++ " " 1);
	x = [0, 1];

	forstep (v = 2, oo, 2,
		ok = 1;
		for (k = 1, #x,
			w = bitxor(v,x[k]);
			if (w==0 || isprime(w),
				ok = 0;
				break;
			);
		);
		if (ok,
			print (n++ " " v);
			x = concat(x, apply(o -> bitxor(o, v), x));
		);
	);
}

quit