arithmetic
The spacing is 6 1+6=7 7+6=13 13+6=19 19+6=25 so the missing number in the sequence is 13
That would be -5.
18
31
27
The spacing is 6 1+6=7 7+6=13 13+6=19 19+6=25 so the missing number in the sequence is 13
2 5 9 10 13 17 19
that best completes the sequence 2 9 5 13 10 19 17 is 27.
2 9 5 13 10 19 17
That would be -5.
18
31
The next number in the sequence is 27.
22
27. But that continues the sequence, it does not complete it.
27
twenty-seven.