(1) plus 1 5 4 20 16 80 (? ) (? ) take it apart to see the parity item, and the question becomes:

1,4, 16,(? ) and 5,20.80. (? )

For 1, 4, 16, (? ) has the following rules:

5-4= 1,20- 16=4,80-64= 16,

That is 4x4 = 16,16x4 = 64;

That'll be $ 5.20.80. (? ) has the following rules:

5、5x4=20、20x4=80

(2) From (1), it can be concluded that they are all multiples of 4.

therefore

Number 7 = 16x4=64

Number 8 =80x4=320

So the rule of the original formula is: unknown value = the second value x4 before the unknown value,

Namely:154201680 (64) (320)