ListPlot[{{1/21, 400}, {1/38, 200}, {1/82, 100}, {1/155, 50}, {1/320, 25}}]

Uh oh! Wolfram|Alpha doesn't run without JavaScript.

Please enable JavaScript. If you don't know how, you can find instructionshere.Once you've done that, refresh this page to start using Wolfram|Alpha.