Answer:
13,-5,-35,-77,-131,-197
Explanation:
To get from 13 to -5, you subtract 18 (or add -18)
To get from -5 to -35, you subtract 30
To get from -35 to -77, you subtract 42
Notice that the amount being subtracted is increasing by 12 each time.
So the next subtraction will be 54, and the one after that will be 66.
So the next term is -77 - 54 = -131
And the term after that is -131 - 66 = -197
So the sequence would be: 13,-5,-35,-77,-131,-197