It calculates Fibonacci. The Fibonacci sequence is a sequence that starts with zero and 1. It adds them to together to get 1, then adds the previous numbers in the sequence(1 and 1) to get 2, and adds the last two numbers in the sequence(1 and 2) to get 3, and so on 0,1,1,2,3,4,7,11,18,... It has many different mathematical purposes, but one of the most obvious is its ability ot calculate accurately the Golden Ratio by dividing the last two numbers in the sequence . To use the program, just set a starting number(you can use 1, which is the traditional fibonacci sequence), and it will add zero to it, then go on. Then, you specify how far you want to calculate. My computer starts the fans at about 100,000. Have fun!