It is well known that round marbles may be put on squares !
I can put my marbles as two equal squares or as two inequal squares
(true squares with at least 4 marbles).
How many marbles ?
Note : Equivallent problems to "find two squares whose arithmetical mean is a square" :
- Find three squares in arithmetic sequence.
- Find a number whose added or substracted to one square gives two other squares.