title: Sum Pairwise Products 2
signature: class Solution {
  
      public decimal SumPairwiseProducts2(int n) {
test_code: using System;
  using System.Numerics;
  using System.Diagnostics;
  using System.Collections.Generic;
  using System.Linq;
  using System.Text;
  using System.Security.Cryptography;
  using System.Web.UI;
  using System.Web.Script.Serialization;
  
  // SOLUTION CODE
  // ============================================
  PLACEHOLDER_CODE_BODY
  
  // TESTING CODE 
  // ============================================
  namespace EvaluatePrediction {
      class TestRunner {
          public bool ValidateSolution(decimal actual, decimal expected){
              return Math.Abs(actual - expected) < 1e-09m;
          }
  
          public string driver(int n, decimal expected){
              try{
                PLACEHOLDER_CLS_NAME solution_cls = new PLACEHOLDER_CLS_NAME();
                decimal pred_result = solution_cls.PLACEHOLDER_FN_NAME(n); 
                if (ValidateSolution(
                      pred_result,
                      expected)){
                  return "PASSED";
                }
                return "FAILED";
              } 
              catch (Exception exception_obj)
              {
                return exception_obj.GetType().FullName;
              }
          }
          static void Main(string[] args) {
              TestRunner runner = new TestRunner();
              String result;
              result = runner.driver(
                  57, 
                  1397887.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-0...{0}",
                  result)
              );result = runner.driver(
                  18, 
                  15675.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-1...{0}",
                  result)
              );result = runner.driver(
                  97, 
                  11449977.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-2...{0}",
                  result)
              );result = runner.driver(
                  9, 
                  1155.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-3...{0}",
                  result)
              );result = runner.driver(
                  42, 
                  420497.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-4...{0}",
                  result)
              );result = runner.driver(
                  67, 
                  2645897.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-5...{0}",
                  result)
              );result = runner.driver(
                  71, 
                  3327486.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-6...{0}",
                  result)
              );result = runner.driver(
                  66, 
                  2493271.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-7...{0}",
                  result)
              );result = runner.driver(
                  69, 
                  2972060.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-8...{0}",
                  result)
              );result = runner.driver(
                  18, 
                  15675.0m
              );
              Console.WriteLine(string.Format(
                  "TEST-9...{0}",
                  result)
              );
          }
      }
  }
  
source_py: def sum_pairwise_products_2(n):
      return ((((n * (n + 1)) * (n + 2)) * ((3 * n) + 1)) / 24)
source_cpp: long long int sum_pairwise_products_2(int n) {
    return n * ( n + 1 ) * ( n + 2 ) * ( 3 * n + 1 ) / 24;
  }