factorial is slower than prod() which is still pretty slow

Why is factorial(n) slower than prod(1:n)? I know with small n (<20) this is the case, but it's kind of annoying. For smallish n, it seems that just building a lookup table is the fastest, but it feels like a bad kluge. Any insights?

Answer 1

[Walter Roberson]

factorial() is defined over matrices and is optimized for that situation. It also has error checking that prod() does not have.