Generate a Yanghui Triangle!

How many rows?

A Triangle of numbers arranged in staggered rows such that each subsequent row is obtained by adding the two entries diagonally above: 
                                    1
                                  1   1
                                1   2   1
                              1   3   3   1
                            1   4   6   4   1
                          1   5  10  10   5   1
                        1   6  15  20  15   6   1
                      1   7  21  35  35  21   7   1
                    1   8  28  56  70  56  28   8   1
The triangle was studied by Blaise Pascal, although it had been described 500 years earlier by Chinese mathematician Yanghui.

Other Yanghui Triangle links:

Eric's Treasure Trove of Mathematics.

Google search for Pascal's Triangle.