1 #include<iostream>
 2 using namespace std;
 3 const int maxn=1005,maxk=20005,p=1e9+7;
 4 int dp[maxn][maxk];
 5 int main(){
 6     dp[1][0]=1;
 7     for(int n=1;n<maxn-1;n++){
 8         dp[n+1][0]=1;
 9         for(int k=0;k<n*(n+1)/2&&k<maxk-1;k++){
10             dp[n+1][k+1]=dp[n+1][k];
11             if(k>=n)
12                 dp[n+1][k+1]-=dp[n][k-n];
13             if(k+1<=n*(n-1)/2)
14                 dp[n+1][k+1]+=dp[n][k+1];
15             dp[n+1][k+1]%=p;
16             if(dp[n+1][k+1]<0)dp[n+1][k+1]+=p;
17         }
18     }
19     int t,n,k;
20     cin>>t;
21     while(t--){
22         cin>>n>>k;
23         cout<<dp[n][k]<<endl;
24     }
25     return 0;
26 }