A positive integer is a whole number (i.e. with no fraction) larger than zero (e.g. 1, 2 or 99)
An example of a Pythagoran triple is 3,4 & 5 (because 3*3 + 4*4 = 5*5)
So multiplying these by the same positive integer will yield more triples, e.g. 6,8 and 10 are also Pythagoran triples since 36 + 64 = 100.
http://statsfiddle.info/