第一个的试解：

change number system base, starting from 2, 3, 4, 5, 6, 7, 8, ....

110 = decimal 6 in base 2.

20 = decimal 6 in base 3.

12 = decimal 6 in base 4.

11 - decimal 6 in base 5,

x = 10 - decimal 6 in base 6.

then followed by 6's.