If n is a positive integer, is n^3 – n divisible by 4?


1) N = 2k+1, where k is an integer


2) N^2 + N is divisible by 6



[spoiler]1. I thought 1 was correct at first, but what if K was 0. Then N = 0+1= 1.

1^3-1 is not divisible by 4. This all depends on if 0 is considered an integer. Ive read various answers on this. Anyone know for sure?[/spoiler]