Another not so difficult problem in Putnam (and it is not the first question in the session!)
Apparently, the format of Putnam in the older years are different. It focused more on direct problem solving and interestingly, the easiest problem was not be the first one. This problem hinges on the usage of the three formulas to generate Pythagorean triples. In the middle of the video, I have proved that the formulas would generate these triples. I will leave it as an exercise for you to show that all integer Pythagorean triples have their corresponding (m,n) to be generated.