- Thread starter Gwyn
- Start date

325 425 650 725 845 850 925 1025 1300 1325 1445 1450

all appear to be multiples of 5 and can be done in only three ways e.g. 325 (the smallest)

1^2 + 18^2 = 325

6^2 + 17^2 = 325

10^2 + 15^2 = 325

As far proving this is concerned I have very little idea how to start!

Was hopping someone might suggest a method or whether a proof already exists. ( I have only minor Knowledge of number Theory)