19, 20, 21, ?, ?, 26, 28, 32, 33, 40

Which two numbers should replace the question marks?

22 and 24: there are two interwoven sequences. 
Starting at 19, alternate numbers progress +2, +3, +4, +5. 
Starting at 20, alternate numbers progress +2, +4, +6, +8.


Viral riddles