18 is the answer and here is why:-
3+1=4
4+2=6
6+3=9
9+4=13
13+5=18
The next number in the sequence is 18. It's +1, +2, +3, +4, ....
18
18
18
18. 3+1=4, 4+2=6, 6+3=9, 9+4=13, 13+5=18.
The rule for this sequence appears to be adding consecutive prime numbers. The sequence starts with 3, then adds the next prime number 2 to get 4. It then adds 3 (the next prime number) to 4 to get 7, then 5 to 7 to get 12, and so on. Each number in the sequence is the sum of the previous number and the next prime number in order.
18 (3+1 4+2 6+3 9+4 13+5)
18
18
The nest number in the sequence is 18. Note that the difference between each number and the next number in the sequence follows the simple sequence of 1,2,3,4. Obviously the next in the sequence of increases is 5, so 13+5=18.
18 Add to previous number by 1 then 2 then 3 then 4 and 5 3+1=4 4+2=6 6+3=9 9+4=13 so then 13+5=18
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