数量关系3,6,29,62,?,214
3,6,29,62,?,2
?=127 1^3 + 2 = 3 2^3 - 2 = 6 3^3 + 2 = 29 4^3 - 2 = 62 5^3 + 2 = 127 6^3 - 2 = 214