Find summation
Practice
3 (5 votes)
Combinatorics
Inclusion Exclusion
C++
Math
Problem
73% Success 580 Attempts 50 Points 5s Time Limit 256MB Memory 1024 KB Max Code
You are given an integer \(n\). Determine the value of the following expression:
\(\sum_{s=0}^{n}\sum_{r=s}^{n}\binom nr\binom rs s^2\)
Here, \(\binom nk\) denotes the number of ways to choose \(k\) objects from a set of \(n\) objects.
Since the value of the expression can be large enough, output it modulo \(10^9 + 7\).
Input format
- The first line contains a single integer \(T\) denoting the number of test cases.
- Each of the next \(T\) lines contains a single integer \(n\).
Output format
The output should contain \(T\) lines each containing the value of the expression for the respective integer \(n\).
Constraints
\(1\le T\le 10^6\\ 1\le n\le 10^{15} \)
Submissions
Please login to view your submissions
Similar Problems
Points:50
14 votes
Tags:
HardMath
Points:20
132 votes
Tags:
Number TheoryEasyMathematicsOpenApprovedFactorization
Points:50
3 votes
Tags:
CombinatoricsHardInclusion-ExclusionMathgenerating functions
Editorial