subtract $1$ to first number to get second number and add $2$ to second number to get third number and this process will continue.
$22-1=21$
$21+2=23$
$23-1=22$
$22+2=24$
$24-1=23$
$23+2=25$
Hence,Next Number will be $25$.
The pattern is as follows:
So the next term will be $25$