Algorithms

Counting k - number of elements, n - number of places
-Sequences - K^n
   -Ordered,Repeating
-Arrangements - n! / (n-k)!
   -Ordered, Non-repeating
-Subsets - (n choose k) = n! / (k! (n-k)!)
   -Non-ordered, Non-repeating
-Multi Subsets - ((n choose k)) = (n+k-1 choose k)
   -Non-ordered, Repeating
  

Division Theorem