I didn't explain that( was edited ), of course you start at with n at 1,2,3... and so forth. But you can decide when to stop, and so I made two cases. Anyway;

I didn't explain that( was edited ), of course you start at with n at 1,2,3... and so forth. But you can decide when to stop, and so I made two cases. Anyway; you gave me a good exercise to practice on. Thanks.