1-a 30
2 (a+1)(b^2+c^2-6)/2(c^2-1)^(1/2)
3-a 4/n(n+1)
4 10+4/pi or 10-4/pi 둘중하나(10은 확정)


확정안된거

1-b 24n^3+156n^2+322n 예상
3-b (4n^4-4n^3-7n^2-24n-88)/n^2(n^2-1)(n^2-2) 예상

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