It is: 34
The next number in this sequence should be 33.
I think its 40
37
This appears to be two interwoven sequences. The first sequence, increases by 9 then 19......7 + 9 = 16........8 + 19 = 27 The second sequence decreases by 8 then 18....16 - 8 = 8........27 - 9 = 18 The next number would thus be 9 + 29 = 38.
29 is the next prime number after 27. But 27 is not a prime! 3 x 9 = 27!
Since there is 16 between the first and second terms and 2 x 16 (32) between the second and third terms, then the forth term should be 3 x 16 (48) higher. The series is 11 27 59 107 171 251...
Next number= 27 X 3 = 81.
13 18 16 21 19 24 22 27 25 ... . This series consists of adding 5 to the first number and subtracting 2 from the next number, repeating the sequence in that order.
The only number in that list which is not a square number is 27. 27 is a cube number.
11 is added to each number in the question in turn, the next number will be 49
It is 27.