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++)

gpf(n) = if (n==1, 1, my (f=factor(n)); f[#f~, 1])

other(p) = {
	see(p);
	my (mx = nextprime(gpf(p)+1));
	for (v=unseen, oo,
		if (!seen(v) && gpf(v) <= mx,
			return (v);
		);
	);
}

v=1; for (n=1, 10 000, print (n " " v); v=other(v))

quit