谢谢uk702!!!
从宝贵的13楼,我们可以知道:
n = 19(21-2), k = 7, 恰好是2个解
n = 31(34-3), k = 8, 恰好是2个解
n = 50(55-5), k = 9, 恰好是2个解
n = 81(89-8), k = 10,恰好是2个解
n = 131(144-13), k = 11,恰好是2个解
n = 212(233-21), k = 12,恰好是2个解
n = 343(377-34), k = 13,恰好是2个解
n = 555(610-55), k = 14,恰好是2个解
n = 898(987-89), k = 15,恰好是2个解