( 2 = (1 |^ 4) + (1 |^ 4) & 17 = (1 |^ 4) + (2 |^ 4) & 97 = (2 |^ 4) + (3 |^ 4) & 257 = (1 |^ 4) + (4 |^ 4) & 641 = (2 |^ 4) + (5 |^ 4) )