因为,
(n+1)³ - n³ = 3n² + 3n + 1
可得,
2^³ - 1³ = 3×1² + 3 + 1
则有,
(n+1)³ - 1 = 3×(1² + 2² + ...... + n²) + 3×(1 + 2 + ...... + n) + n
n³ + 3n² + 3n = 3×(1² + 2² + ...... +n²) + 3(n + 1)n/2 + n
整理后可得,
1² + 2² + 3² + ...... + n² = n(n+1)(2n+1)/6
所以,
1² + 2² + 3² + ...... + 10²
= 10 × 11 × 21 / 6
= 385