Finding the General Statement

Consider the five rows of numbers....

1 1

1 3/2 1

1 6/4 6/4 1

1 10/7 10/6 10/7 1

1 15/11 15/9 15/9 15/11 1

Let En(r) be the (r+1)th element in the nth row, starting with r=0. Example: E5(2) = 15/9

Find the General Statement for En(r).

Discuss the scope and limitations of the general statement.

I found the general statement by looking at the nth term of the numerators as this was dependent upon only n. I then found the difference between the num and dem in terms of n and r, so I could express it as a single term. It came to...

En(r) = (n^2+n)/(n^2+n-2rn+2r^2)

I believe this is correct. Nevertheless, I also need to find this general statement **graphically **and am uncertain of how to accomplish this. I would appreciate any suggestions.

I understand a limitation is that the general statement is valid only for

r<(or equal to) n. However, I have heard there are **more limitations **and would appreciate any suggestions.

Thank you in advance. (This is a more refined version of a question I previously posted, which received no responses. I have tried to make it more appealing this time.)