Combinatorics
N
Factorial
N
Combination
N
Permutation
N
Binomial coefficient
St
Result
St
The pigeonhole principle
\(\frac{n!}{k!(n-k)!}\)
Combination
Permutation
Binomial coefficient
Result
\[{{2}^{n} = \binom{n}{0} + \binom{n}{1} + \binom{n}{2} + \dots{} + \binom{n}{n}}\]