4
The next number in the sequence is 27.
The sequence appears to be decreasing by 2, then increasing by 5, and then decreasing by 2 again. Following this pattern, after 19, the next number would follow the same decrease of 2. Therefore, the next number in the sequence is 17.
I think that the next number in the sequence is 360.
20
5
The sequence is decreasing by a factor of 5 each time, so the next number would be -2.
21
The next number in the sequence is 480
46657
1+1=2 : 1+2=3 : 2+3=5 : 3+5=8Therefore the next number is 8
The next number in the sequence is 6. The sequence alternates between adding 3 and subtracting 1 from the previous number.
The next number in the sequence 5-7-13-31 is 69.