Find the missing number in the following series

Q41. 1, 2, 2, 4, 8, ?

1. 24
2. 9
3. 32
4. 36

Q42. 8, 12, 18, 27, ?

1. 36
2. 44
3. 37.5
4. 40.5

Q43. 2, 5, ?, 27, 58, 121

1. 10
2. 11
3. 12
4. 14

Q44. 9, 27, 31, 155, 161, 1127, ?

1. 1288
2. 1316
3. 2254
4. 1135

Q45. 4, 2, 2, 3, 6, 15, ?

1. 35
2. 40
3. 45
4. 50

Q46. 13, 40, 122, 369, ?

1. 1110
2. 1111
3. 1112
4. 1113

Q47. 2, 10, 60, 420, 3360, ?

1. 30440
2. 30244
3. 30220
4. 30420

Q48. 10, 18, 34, ?, 130, 258

1. 32
2. 60
3. 68
4. 66

Q49. 2, 8, 26, ?

1. 81
2. 80
3. 132
4. 321

Q50. 8, 29, 113, 449, ?

1. 673
2. 984
3. 1484
4. 1793