Like Pascal's Triangle, sort of. Let row 1 be 1,1, and let row 2 be 1,2,1 and let row 3 be 1,3,2,3,1 and row 4 be 1,4,3,5,2,5,3,4,1, etc. In other words, each new row takes the row above and inserts the sum of the adjacent numbers.

a. There are interesting patterns in this table. Investigate a few!

b. More specifically, how many times does n appear in row n?