Subtract 20, 25, 30, 35, 40, 45 from successive numbers. So 0 is wrong.

There are two series (8, 11, 14, 17, 20) and (7, 12, 17, 22). Increasing by 3 and 5 respectively.

Number are alternately multiplied by 3 and divided by 2. So, next number = 54 / 2 = 27.

Each number is double the preceding one plus 1. So, the next number is (255 x 2) + 1 = 511.

There are two series, beginning respectively with 3 and 7. In one 3 is added and in another 2 is subtracted. The next number is 1 - 2 = - 1.

Each number is twice the preceding one with 1 added or subtracted alternately.
So, the next number is (2 x 261 + 1) = 523.

Go on subtracting 3 and dividing the result by 2 to obtain the next number. Clearly, 46 is wrong.

Go on adding 7, 9, 11, 13, 15, 17 respectively to obtain on the next number. So, 33 is wrong.

Go on subtracting 24, 21, 18, 15, 12, 9 from the numbers to get the next number. Clearly,128 is wrong.

Numbers are (2³ - 1), (3³ - 1), (4³ - 1) (5³ - 1), (6³ - 1) (7³ - 1) etc.
So, the next number is (8³ - 1) = (512 - 1) = 511.