Like Doc hinted, do you really have to use this thermistor for your project? This thing will draw 500mA even with a proper serial resistor. That is the upper limit of USB connection. You should be using this in line with large current applications. Any chance to use a good old 10K ohm thermistor instead?

The best accuracy can be obtained by finding the resistance of 20C and 70C, then find the average of the log of the two resistance and take exponent. One example, at 20C resistance is 1000, at 70C resistance is 10. Then the base 10 logs are 3 and 1. So average is 2. Take 10 exponent of 2 you should be using 100 ohm resistor. I remember this from deriving the errors of voltage divider resistance measurement for my electronics class. I also have enough data to show it.