7, 26, 63, 124, 215, 342, ?

4, 10, 40, 190, 940, ? , 23440

Complete the series choosing the missing letter

ab__b__aa__b__ba

Select the number that can replace the question mark (?) in the following series.

31, 44, 58, 73, 89, ?

2, 6, 12, 20, 30, 42, 56, ?

3, 18, 15, 24, 35,?....

Find the missing number?

32, 44, 58, 74, 92, 112, (?)