Problem J. huntian oy
时间限制 2000 ms
内存限制 64 MB
One day, Master oy created a new function to celebrate his becoming a 'huntian' in majsoul.
$f(n,a,b)=\sum_{i=1}^n \sum_{j=1}^i gcd(i^a-j^a,i^b-j^b)[gcd(i,j)=1]\%(10^9+7)$
Given n, a and b, Master oy wanted Newbie jj who was still a 'chuxin' to answer the value of $f(n,a,b)$.
输入数据
输出数据
For each test case, an integer in one line representing your answer.
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样例输出
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