Does 362880 = 9! = 2^7*3^4*5*7? Recognizing and Factoring factorials

Greg Fee, CECM

3:30pm, Wednesday May 21st, P9309 / P9318 (the Dean's old office space)



Abstract: 
Maple can easily compute and factor small factorials,
but it starts to slow down after ifactor(100000!).
Maple can compute one million factorial (1000000!) in about 1 second,
but I killed it after one day when I attempted to factor it.
Can we do better?
Yes, first we create a procedure to recognize that a given
positive integer is a factorial, that is we solve
the equation n!=a for n with numerical methods,
then we just feed n (not n!) into a special factorial factor procedure.