Pascal\u27s Arithmetical Triangle

In almost all books on College Algebra, the Pascal Triangle is placed in such a position as to show the binomial coefficients in a horizontal line. This position is appropriate when the only use of the triangle is to help students remember these coefficients; but Pascal had a wider purpose in mind. Pascal\u27s Construction. Pascal first sets up a lattice-work consisting of equal squares, assigning to each square a definite positive integer which he determines as follows. 1. The number in each square of the 1st (top) row, and also in each square of the 1st (left-hand) column is to be unity. 2. To each other square is assigned an integer determined by the recurrence relation which he states thus: The number in any other square is equal to the sum of the two numbers immediately to the left, and immediately above it