Solution: -344 equals to the cube of -7 minus1; 17 equals the square of -4 plus1; -2 equals to-1 minus the cube of 1; 5 equals the square of 2 plus1; 65 is equal to the square of 8 plus 1, indicating that it is a hidden sequence -7, -4,-1, 2, (), 8 and the arrangement law of odd-numbered cube-1 and even-numbered square+1. The hidden sequence is a arithmetic progression with a tolerance of 3, indicating that the hidden sequence is missing.

This question has a high difficulty coefficient and belongs to the category of competition questions. Of course, divergent thinking is not ruled out, and there are other relatively simple and clear laws.