How much will the determinant of the matrix 20x20 be considered, when calculating "by definition"?

Question

Linear algebra

Tell me, please, how to calculate this if the power of the computer is known?

Answer 1

Forty yes forty - ruble forty,
They took matches - No - Two rubles from you.
So I didn't take it!
If they took it, it would be six.

On a computer with a power of 50 watts - quickly.
UPDATE:
Oh, Artyomka, and no one is going to help you, and you yourself are not boom-boom. But he solved problems with recursion.
Well, let's count the number of multiplications when calculating the determinant of the matrix "by definition":

def f(n):
    return 0 if n == 1 else f(n - 1) * n + n

print(f(20)) #  4180411311071440000