big = 1 000 000
s = 0
S = []
unseen = 1
seen(v) = if (v < big, bittest(s, v), setsearch(S, v))
see(v) = if (v < big, s = bitor(s, 2^v), S = setunion(S, [v])); while (seen(unseen), unseen++)

n = 0
a = vector(5000)
emit(v) = {
	print (n++ " " v);
	see(v);
	if (n <= #a,
		a[n] = v;
	);
}

{
	emit(1);
	for (n = 1, #a,
		for (v = unseen, oo,
			if (!seen(v) && !seen(w = bitor(v, a[n])) && v!=w,
				emit(v);
				emit(w);
				break;
			);
		);
	);
}

quit