Here we have all the programs from the two books:

Implementing Discrete Mathematics: Combinatorics and Graph Theory with Mathematica by Steven S. Skiena, Addison-Wesley Publishing Co., Advanced Book Program, 350 Bridge Parkway, Redwood City CA 94065. ISBN 0-201-50943-1.

This is the older two books and we have V0.9 code for that as CombinatoricaV0.9.m

The revised edition of this is:

Computational Discrete Mathematics: Combinatorics and Graph Theory in Mathematica, by Sriram V. Pemmaraju and Steven S. Skiena, Cambridge University Press, 2003.

We have V.2.0 or that as CombinatoricaV2.0.0.m

To run from inside Mathics3:

$ git clone [email protected]:Mathic3/Mathics3-Combinatorica.git
$ cd Mathics3-Combinatorica/Combinatorica

$ mathics

Mathics 7.0.1dev0
on CPython 3.12.10 ...
...
In[1]:= << CombinatoricaV2.0.0.m (* Or CombinatoricaV0.9.m *)
...

In[2]:= Permutations[3]
Out[2]= {{1, 2, 3}, {1, 3, 2}, {2, 1, 3}, {2, 3, 1}, {3, 1, 2}, {3, 2, 1}}

In[3]:= Permute[{A,B,C,D}, Permutations[3]]
Out[3]= {{A, B, C}, {A, C, B}, {B, A, C}, {B, C, A}, {C, A, B}, {C, B, A}}