#include #include #include #define MAX 10000007 #define LL __int64 using namespace std; int n; LL a[MAX]; int main() { LL t,m,i,j,sum,xx=1000000007; scanf("%I64d",&t); while(t--) { scanf("%I64d",&n); for(j=1; j<=n; j++) { scanf("%I64d",&a[j]); } a[0] = 0; for(j=1;j<=n;j++) { a[j] = a[j]*j+a[j-1]; a[j] = a[j]%xx; } sum = 0; for(j=1;j<=n;j++) { sum = sum+a[j]; sum = sum%xx; } printf("%I64d\n",sum); } return 0; }