Aptitude - Odd Man Out and Series

Go on adding 7, 9, 11, 13, 15, 17, 19 respectively to obtain the next number.

So, 135 is wrong.

2^nd term = (1^st term) x 1 + 1 = 15 x 1 + 1 = 16.

3^rd term = (2^nd term) x 2 + 2 = 16 x 2 + 2 = 34.

4^th term = (3^th term) x 3 + 3 = 34 x 3 + 3 = 105.

5^th term = (4^th term) x 4 + 4 = 105 x 4 + 4 = 424

6^th term = (5^th term) x 5 + 5 = 424 x 5 + 5 = 2125

6^th term should 2125 instead of 2124.

2^nd term = (1^st term) x 3 - 4 = 10 x 3 - 4 = 26.

3^rd term = (2^nd term) x 3 - 4 = 26 x 3 - 4 = 74.

4^th term = (3^th term) x 3 - 4 = 74 x 3 - 4 = 218.

5^th term = (4^th term) x 3 - 4 = 218 x 3 - 4 = 650.

5^th term must be 650 instead of 654.

Go on dividing by 6, 5, 4, 3, 2, 1 respectively to obtain the next number.

Clearly, 92 is wrong.

Go on multiplying the number by 2 and adding 1 to it to get the next number.

So, 27 is wrong.