18
49, 36, 25...
The next number is 49+8 = 57
45 54
The next number in the series 4, 12, 6, 12, 36, 18, 36
The next number in the series 4-12-6-12-36-18-36.. is 108.
It is: 36 because 6 squared = 36
108
36
The series goes like this 2 = 1^2 + 1^3 (1 square + 1 cube) 12 = 2^2 + 2^3 36 = 3^2 + 3^3 and so on.. So, the next number in the series is 6^2 + 6^3 = 252.
108
108