Definition:Pascal's Triangle

Definition
Pascal's Triangle is an array formed by the binomial coefficients:


 * $\begin{array}{r|rrrrrrrrrr}

n & \binom n 0 & \binom n 1 & \binom n 2 & \binom n 3 & \binom n 4 & \binom n 5 & \binom n 6 & \binom n 7 & \binom n 8 & \binom n 9 & \binom n {10} & \binom n {11} & \binom n {12} \\ \hline 0 & 1 &  0 &  0 &   0 &   0 &   0 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 1  & 1 &  1 &  0 &   0 &   0 &   0 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 2  & 1 &  2 &  1 &   0 &   0 &   0 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 3  & 1 &  3 &  3 &   1 &   0 &   0 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 4  & 1 &  4 &  6 &   4 &   1 &   0 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 5  & 1 &  5 & 10 &  10 &   5 &   1 &   0 &   0 &   0 &  0  &  0 &  0 & 0 \\ 6  & 1 &  6 & 15 &  20 &  15 &   6 &   1 &   0 &   0 &  0  &  0 &  0 & 0 \\ 7  & 1 &  7 & 21 &  35 &  35 &  21 &   7 &   1 &   0 &  0  &  0 &  0 & 0 \\ 8  & 1 &  8 & 28 &  56 &  70 &  56 &  28 &   8 &   1 &  0  &  0 &  0 & 0 \\ 9  & 1 &  9 & 36 &  84 & 126 & 126 &  84 &  36 &   9 &  1  &  0 &  0 & 0 \\ 10 & 1 & 10 & 45 & 120 & 210 & 252 & 210 & 120 &  45 &  10 &  1 &  0 & 0 \\ 11 & 1 & 11 & 55 & 165 & 330 & 462 & 462 & 330 & 165 &  55 & 11 &  1 & 0 \\ 12 & 1 & 12 & 66 & 220 & 495 & 792 & 924 & 792 & 495 & 220 & 66 & 12 & 1 \\ \end{array}$

Column
Thus the entry in row $n$ and column $m$ contains the binomial coefficient $\dbinom n m$.

Also presented as
Pascal's Triangle is often presented in a symmetrical form, in which the columns and diagonals are both presented in a diagonal form:


 * [[File:PascalsTriangle.gif]]

While this is a visually more appealing presentation, as well as being more intuitively clear, it can be argued that it is not as straightforward for investigating its properties as the canonical presentation preferred on.

Also see

 * Pascal's Rule
 * Definition:Stirling's Triangles