upto(n) = {my(l = List(), res = vector(10)); res[1] = 8;
	for(e = 3, logint(n, 2),
		for(k = 2, sqrtnint(n, e), 
			listput(l, k^e)
		)
	);
	l = Set(l);
	for(i = 2, #l, 
		c = squaresbetween(l[i-1], l[i]);
		if(c > #res, 
			res = concat(res, vector(c - #res));
		);
		if(c > 0 && res[c] == 0, 
			res[c] = l[i]
		)
	); res
}

squaresbetween(k, m) = {
	sqrtint(m) - ceil(sqrt(k)) + 1 - issquare(m) - issquare(k)
}