Solved use the formulae ∑j=1Nj=2N(N+1)∑j=1Nj2=6N(N+1)(2N+1) | Chegg.com

Solved use the formulae ∑j=1Nj=2N(N+1)∑j=1Nj2=6N(N+1)(2N+1) | Chegg.com