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

\\ least k unseen / v AND k = 0
cc = [0]
avoid(v) = {
	if (!seen(0),
		return (0);
	);
	my (b, c, nb=1);
	for (e=0, oo,
		if (!bittest(v,e),
			if (nb==#cc,
				cc=concat(cc, vector(#cc));
			);
			b=2^e;
			for (k=1, nb,
				c = cc[nb+k] = cc[k]+b;
				if (!seen(c),
					return (c);
				);
			);
			nb*=2;
		);
	);
}

{
	m=0;
	for (n=1, 141,
		x = 0;
		for (k=1, n,
			see(v = avoid(x));
			print (m++ " " v);
			x += v;
		);
	);
}

quit