allocate mem(2^32)

{
	a = vector(2^13);
	u = 0;

	ord = [0];
	for (n=1, oo,
		if (n==1,
				v = 0,
				v = bitxor(v, ord[1+v]-1);
		);
		while (#ord < 1+v,
			ord = concat(ord, vector(#ord));
		);
		ord[1+v]++;

		if (1+v<=#a && !a[1+v],
			a[1+v] = n;
			while (a[1+u]>0,
				print (u " " a[1+u]);
				if (1+u==#a,
					break (2),
					u++;
				);
			);
		);
	);
}

quit