1 x 2 x 3 + 2 x 3 x 4 + 3 x 4 x 5 +...+ 8 x 9 x 10

1 x 2 x 3 + 2 x 3 x 4 + 3 x 4 x 5 +...+ 8 x 9 x 10

1 × 2 × 3 + 2 × 3 × 4 + 3 × 4 × 5 +...+ 8 × 9 × 10 = (1 / 4) (1 × 2 × 3 × 4) + (1 / 4) (2 × 3 × 4 × 5 - 1 × 2 × 3 × 4) + (1 / 4) (3 × 4 × 5 × 6 - 2 × 3 × 4 × 5) +...(1 / 4) (8 × 9 × 10 × 11 - 7 × 8 × 9 × 10) = (1 / 4) (1 × 2 × 3 × 4 + 2 × 3 × 4 × 4 × 5 - 1 × 2 × 3 × 4 + 3 × 4 × 5 × 6 -...