5/11 = 1/11 + 4/11
5/11 = 2/11 + 3/11
- - - - - - - - - - - -
7/9 = 1/9 + 6/9
7/9 = 2/9 + 5/9
7/9 = 3/9 + 4/9
9/13 = 1/13 + 8/13
9/13 = 2/13 + 7/13
9/13 = 3/13 + 6/13
9/13 = 4/13 + 5/13
6/17 = 1/17 + 5/17
6/17 = 2/17 + 4/17
6/17 = 3/17 + 3/17
P=(a+b)2