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Line 4: 1 2 1 1 3 3 1 The first element in each row is 1. Some people count it as zero, but it only makes since to have one as the first element where each element of each row is either 1 or the sum of the two elements right above it. For example, the next row would be 1 (since the first element of each row doesn't have two elements above it), 4 (1 + 3), 6 (3 + 3), 4 (3 + 1), and 1 (since the last element of each row doesn't have two elements above it). Each row <tt>n</tt> (starting with row 0 at the top) shows the coefficients of the binomial expansion of (x + y)<sup>n</sup>. Write a function that prints out the first n rows of the triangle (with <tt>f(1)</tt> yielding the row consisting of only the element 1). This can be done either by summing elements from the previous rows or using a binary coefficient or combination function. Behavior for <tt>n <= 0</tt> does not need to be uniform, but should be noted.

Pascal's triangle: Difference between revisions

Pascal's triangle (view source)