Input (grade 13): Furthermore, any even perfect number except the first one is the ((2p +1) \/O/ 3) th centered nonagonal number as well as the sum of the first 2 (pâ '1) \/O/ 2 odd cubes:
Output (grade 7): Also, any even perfect number except the first one is the sum of the first 2 (n 1) \/O/ 2 odd cubes: