This Brain Game is (in my opinion) more difficult than most. Consider it a Friday challenge! Good luck:

What is the next number in this sequence?

1, 3, 8, 20, 50, 125, 313, ?

Here is my SOLUTION.

MY ANSWER:

 

783.

Where X is the previous number, the pattern is:  X × 2.5 (rounded to the closest integer).