Question #6200191

# How many digits has the sum of the first factorials?

**(a)
How many digits has the number s defined below?
s = 0! + 1! + 2! + 3! + 4! + ... + (n-1)! + n!
(b)
define:
â‚™
âˆ‘ i! = s(n)
â±â¼Â¹
prove that
s(n) â‰¡ 4 (mod 10) for any integer n > 3
**

TELL US , if you have any answer

Sponsored ads