upto(n) = {my(res = List(), lv, uv, ind = 0, i = 3);
	while(1,
		t = 2*i^2;
		lv = t;
		while(oddrank(lv-1) == 1,
			lv--;
		);
		if(lv > n, 
			return(res)
		);
		uv = t;
		while(oddrank(uv + 1)==1,
			uv++;
		);
		for(i = lv, uv - 3, 
			listput(res, i);
		);
		i+=2
	);
}

oddrank(n) = {
	my(f = factor(n)); sum(i = 1, #f~, bitand(f[i,2], 1))
}