\begin{tabularx}{\linewidth}{|XXXX|} \hline \multicolumn{4}{|c|}{Binomialkoeffizienten} \\ \hline \multicolumn{4}{|c|}{ $\frac{n!}{k!(n - k)!} \hfill=\hfill \binom{n}{k} \hfill=\hfill \binom{n}{n - k} \hfill=\hfill \frac{n}{k}\binom{n - 1}{k - 1} \hfill=\hfill \frac{n-k+1}{k}\binom{n}{k - 1} \hfill=\hfill \binom{n - 1}{k} + \binom{n - 1}{k - 1} \hfill=\hfill (-1)^k \binom{k - n - 1}{k} \hfill\approx\hfill 2^{n} \cdot \frac{2}{\sqrt{2\pi n}}\cdot\exp\left(-\frac{2(x - \frac{n}{2})^2}{n}\right)$ } \\ \grayhline $\sum\limits_{k = 0}^n \binom{n}{k} = 2^n$ & $\sum\limits_{k = 0}^n \binom{k}{m} = \binom{n + 1}{m + 1}$ & $\sum\limits_{i = 0}^n \binom{n}{i}^2 = \binom{2n}{n}$ & $\sum\limits_{k = 0}^n\binom{r + k}{k} = \binom{r + n + 1}{n}$\\ $\binom{n}{m}\binom{m}{k} = \binom{n}{k}\binom{n - k}{m - k}$ & $\sum\limits_{k = 0}^n \binom{r}{k}\binom{s}{n - k} = \binom{r + s}{n}$ & \multicolumn{2}{l|}{ $\sum\limits_{i = 1}^n \binom{n}{i} F_i = F_{2n} \quad F_n = n\text{-th Fib.}$ }\\ \hline \end{tabularx}