20 is the next number greater than 19. The next prime number greater than 19 is 23.
If you mean: 9, 19, 39, 69 then the next number in the sequence is 109
26
7
The next figure would be 21, followed by 11 & 10.
20 is the next number greater than 19. The next prime number greater than 19 is 23.
31
25-1=24 24-2=22 22-3=19 19-4=15 15-5=10 The next number in the series is 10.
If you mean: 9, 19, 39, 69 then the next number in the sequence is 109
53
35
26
67
31.............[15+1=16, 16+3=19, 19+5 =24, 24+7=31]
27
27
10