Subtract two, multiply by two, subtract one. :)
12-13-15 etc.... The sequence is add 1 then add 2
14
31
11, -10, 9
15
20
The number which best completes the sequence below is: 2 9 5 13 10 19 17 ?
11
11
11.
21
15
22
What number best completes the sequence 1 1/2 5 10 1/2 18
10,20,30,20
The next number in the sequence is 27.
12-13-15 etc.... The sequence is add 1 then add 2