Explanation:

series  4,10,14,(),62,126
 
 4 ×2+2=10
 first number is multiply by 1 and added 2 
 6 ×2+2=14
 second number is  multiply by 2 and added 2
 14 ×2+2=30
 30× 2+2=62
 62× 2+2=126
 common in series 2 is muliply and added 2
 30 is missing