Actually 2**N is the number of subsets of a set of cardinality N, while the number of permutations of a set of N distinct elements is N! (facultyfactorial).
ivancho used the subset theme quite succesfully in this node above.
In reply to Re^2: Obtaining terms in an expansion
by pKai
in thread Obtaining terms in an expansion
by randyk
| For: | Use: | ||
| & | & | ||
| < | < | ||
| > | > | ||
| [ | [ | ||
| ] | ] |