HP 42S manual

For a integer number we have Γ(n)=(n-1)! and Γ(n+1)=n!. The number in gamma function must be real.

In this point HP-42S is different from 33S which has only one function for both things.

RAN: This is the random number generator which gives a pseudo-random number in 0≤x≤1.

SEED: A sequence of pseudo-random numbers always starts with a seed. If you repeat the seed the sequence repeats. To enter a new seed just enter a number and press SEED.

If the seed is zero the calculator will generate another seed.