N = 4 6 8 3 4 2 18 + + + = 12 8 3 4 4 6 4 2 2 + + + + + = = (...

83. N = 4 6 8 3 4 2 18 + + + = 12 8 3 4 4 6 4 2 2 + + + + + =

= ( 2 3 2 + )

2

+ 2 2 2 3 2 ( + + = ) 2 ( 2 3 2 + + 2 )

2

= 2 3 + 2 2 + .