1 , 2 , 3 , 5 , 9 , 12 , ?

Keep practicing — related questions

• 1, 4, 6, 9, 11, 14, 16, 19, x
• 0, 1, 3, 6, 10, 15, x
• 0, 1, 3, 6, 10, 15, x
• 1, 4, 6, 9, 11, 14, 16, 19, x
• 5 , 4 , 20 , 7 , 2 , 14 , 3 , 6 , ?
• 3, 5, 7, 12, 17, 19
• 2,5,9,14,...
• 1 1 2 4 7 11..........