21 It is the Fibonacci secuence.1+1=2 1+2=3 2+3=5 and so on... 1,1,2,3,5,8,13,21,34,55,89,144,233,377,610...
The next number is -21
the answer will be 21
10
225
This is the series of square numbers, (16= 4*4). The next number is 5*5=25.
21
21
21
21.
A single number, such as 12848384 does not make a series.
The next number is 25 but there are the sequence is infinite so there can be no end to the sequence.
12,14,16,18,20,22,24,26,28,30,32,34,36,38,40,42,44,46,48,50