Find the law according to the sequence 1. Root 2, - root 3, root 2, root 5, - root 6, root 7 Observe the sequence and say a rule of arrangement

Find the law according to the sequence 1. Root 2, - root 3, root 2, root 5, - root 6, root 7 Observe the sequence and say a rule of arrangement

1,2,3,4,5,6,7. Every number has a root, and every multiple of 3 is preceded by a negative sign
I can see that

5 ,5 ,14 ,38 ,87 ,（ ）

5 5 14 38 87 ()
Answer 167
5 5 14 38 87 167
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9 24 49 80
0 =1^2-1
9 =3^2
24=5^2-1
49=7^2
80=9^2-1

5,5 ,14,38,87_ What number should be behind to find the law
5: (- 1) * (- 1) + 45:1 * 1 + 414:3 * 3 + 1 * 1 + 438:5 * 5 + 3 * 3 + 487:7 * 7 + 5 * 5 + 3 * 3 +: 9 * 9 + 7 * 7 + 5 * 5 + 4 = 159 I don't know my solution, please correct me

The remainder of 5,5,14,38,87, () divided by 4 is 1,1,2,2,3,3“