s = 0
unseen = 1
seen(v) = bit test(s, v)
see(v) = s = bit or(s, 2^v); while (seen(unseen), unseen++)

base = 10
head = 1

other(p) = {
	see(p);
	for (v=unseen, oo,
		if (!seen(v),
			my (q=v/p);
			while (q<1,
				q*=base;
			);
			if (digits(floor(q), base)[1]==head,
				return (v);
			);
		);
	);
}

v=1; for (n=1, 1000, print (n " " v); v=other(v));

quit