To Prove It,
Sorry if i gave the impression i didn't even try, but seriously the community's really great here and i'm looking forward to help others out in future..
I tried my hand at it but only got into summation of recurrence terms- and though using method of differences pretty cuts it down alot, i just can't show the result. i do know that sum to n of r^2 is 1/6n(n+1)(2n+1).