sequences and sum of squares C1

OCR MEI C1 June 13 Q9, need help with part ii

n - 1, n and n + 1 are any three consecutive integers.
(i) Show that the sum of these integers is always divisible by 3.
(ii) Find the sum of the squares of these three consecutive integers and explain how this shows that the
sum of the squares of any three consecutive integers is never divisible by 3

So show that $(n-1)^2+n^2+(n+1)^2$ is never divisible by 3.