big = 1 000 000
s = 0
S = Set([])
unseen = 1
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++)

other(pp,p) = {
	my (mandatory=vecmax(digits(pp)),
	    forbidden=Set(digits(p)));
	for (v=unseen, oo,
		if (!seen(v),
			my (vdig=Set(digits(v)));
			if (setsearch(vdig, mandatory) && #setintersect(vdig, forbidden)==0,
				return (v);
			);
		);
	);
}

for (n=1, 25 000, v=if (n<=2, n, other(pp, p)); see(v); print (n " " v); [pp, p] = [p, v])

quit