procedure PascalsTriangle: Pascal triangle row
link pascltri
August 7, 1997; Erik Eid
This file is in the public domain.
The procedure, when invoked by a call to PascalsTriangle(n), returns
the nth row of Pascal's Triangle in list form. Pascal's Triangle is a
mathematical structure in which each element of a row is the sum of the
two elements directly above it. The first few levels are:
Row 1: 1 Triangle stored as: [[1],
2: 1 1 [1, 1],
3: 1 2 1 [1, 2, 1],
4: 1 3 3 1 [1, 3, 3, 1],
5: 1 4 6 4 1 [1, 4, 6, 4, 1]]
For example, PascalsTriangle(4) would return the list [1, 3, 3, 1].
The procedure fails if n is not an integer or if it is less than one.