4000 Followers Problem!
Number Theory
Level
5
\[\large a! + b! + c! = a! \cdot b!\]
If \(a,b,c\) are nonnegative integers, then there are a finite number of solutions to the above equation. Let them be \((a_1, b_1, c_1), (a_2, b_2, c_2), (a_3, b_3, c_3), \ldots, (a_n, b_n, c_n)\) in some order. Find the value of
\[n + \displaystyle \sum_{i=1}^n (a_i+b_i+c_i ).\]
(If \(n = 0\), then the sum is zero, so you should write 0 as the answer.)
by
Sharky Kesa