I once had learned a formula to calculate the number of pieces in a triangle with n pieces at the base (e.g., rows from top to bottom had 1, 2, 3, 4... n pieces). E.g.: how many bricks to form a triangle with 10 bricks at the base? That is 1+2+3+4+5+6+7+8+9+10. Now imagine calculating that for a triangle with 100…