Combinatoria: Variaciones, Combinaciones y Permutaciones

$$ \left\{\begin{array}{l} \hbox{Importa el orden} \left\{\begin{array}{l} \hbox{No entran todos } \mathbf{\hbox{(Variaciones)}} \left\{\begin{array}{l} \hbox{Sin repetición: } V_{n,k}=\displaystyle{\frac{n!}{(n-k)!}}=n \cdot (n-1) \cdots (n-k+1)\\ \hbox{Con repetición: } VR_{n,k}=n^k \end{array}\right.\\ \\ \hbox{Entran todos } \mathbf{\hbox{(Permutaciones)}} \left\{\begin{array}{l} \hbox{Sin repetición: } P_{n}=n! = n \cdot (n-1) \cdot (n-2) \cdots 2 \cdot 1\\ \hbox{Con repetición: } PR_{n}^{\alpha_1,\alpha_2,\cdots,\alpha_k}=\displaystyle{\frac{n!}{\alpha_1! \cdot \alpha_2!\cdots \alpha_k!}} \end{array}\right.\\ \end{array}\right.\\ \\ \hbox{No importa el orden } \mathbf{\hbox{(Combinaciones)}} \left\{\begin{array}{l} \hbox{Sin repetición: } C_{n,k} = \displaystyle{\binom{n}{k}} = \displaystyle{\frac{n!}{(n-k)! \cdot k!}}\\ \hbox{Con repetición: } CR_{n,k} = C_{n+k-1,k} = \displaystyle{\binom{n+k-1}{k}} = \displaystyle{\frac{(n+k-1)!}{(n-1)! \cdot k!}}\\ \end{array}\right.\\ \end{array}\right. $$ $$ \left.\begin{array}{l} \mathbf{\hbox{ (Permutaciones circulares) }} PC_n=(n-1)!\\ \end{array}\right. $$

Números Combinatorios

$$\left\{\begin{array}{l} \mathbf{\hbox{(Factorial de n) }} n! = n \cdot (n-1) \cdot (n-2) \cdots 2 \cdot 1 \hbox{ , } \forall n \in \mathbb{N}\\ \mathbf{\hbox{(Propiedades)}} \left\{\begin{array}{l} n! = n \cdot (n-1)!\\ 0! = 1\\ \end{array}\right.\\ \mathbf{\hbox{(Número combinatorio) }} \hbox{Dados n, m} \in \mathbb{N},n \geq m, \displaystyle{\binom{n}{m}} = \displaystyle{\frac{n!}{m!(n-m)!}} \\ \mathbf{\hbox{(Propiedades)}} \left\{\begin{array}{l} \displaystyle{\binom{n}{0}} = 1, \hbox{ } \displaystyle{\binom{n}{1}} = n, \hbox{ } \displaystyle{\binom{n}{n}} = 1\\ \displaystyle{\binom{n}{m}} = \displaystyle{\binom{n}{n-m}}, \hbox{ } \displaystyle{\binom{n}{m}} + \displaystyle{\binom{n}{m+1}} = \displaystyle{\binom{n+1}{m+1}}\\ \end{array}\right.\\ \end{array}\right. $$

Triángulo de Tartaglia (o de Pascal)