Can someone help me with this ?

12 + 8 = 20 , 20 + 8 = 28 , 28 + 8 = 36
5 + 8 = 13 , 13 + 8 = 21 , 21 + 8 = 29
Answer:
29
Step-by-step explanation:
The sequence of values
5 , 13, 21 , ?
The values are increasing by 8 so missing value is
? = 21 + 8 = 29