Which SQL keyword removes duplicate rows automatically

Find the missing number in the given number series.

1, 2, 6, 24, 120, ?

140, 146, 158, 176, ?, 230

7, 6, 10, 27, 104, ? 

What will come in place of the question mark (?) in the following series?

11, 13, 19, ?, 51, 81

48, 95, 283, 1129, ?, 33841

22, 37, 63, 98, 148, ?

12, 19, 32, ?, 76, 107

What will come in place of the question mark (?) in the following series?

130, 158, 214, 298, ?, 550

45, 58, 84, 123, ?, 240 

What will come in place of the question mark (?) in the following series?

4, 11, 32, 95, 284, 851, ?