You want a formula to solve the recursive formula `F(n) = F(n-1) + ((n-1) * 5000)`

There may be many ways to solve your question; consider this as one solution.

This answer uses a "custom formula" `wa14322603()`. 
 - Enter the formula in a cell and point the input value to a cell containing an integer. The formula will return the value of the recursive formula.


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    /**
     * Applies the input value to the recursive formula
     *
     * @param {number} input The value to use in the recursion
     * @return The input applies to the recursion.
     * F(0) = 0
     * F(1) = 5000
     * F(n) = F(n-1) + ((n-1) * 5000)
     * @customfunction
     */
    function wa14322603(input) {
    
      // create a temporary array to hold values
      var resultarray=[];
      
      // assign F(0)
      resultarray.push(0);
      
      // assign F(1)
      resultarray.push(5000)
      
      // define the multiplier
      var multiplier = 5000;
      
      if (input===0){
        var result = resultarray[input]
      }
      
      if (input === 1){
        var result = resultarray[input]
      }
      
      if (input>1){
    
        // calculate the number of tertaions required
        var iterate=input+1;
    
        for (var i=2; i<iterate;i++){
        
          // calculate f(n-1}
          var fn_1=resultarray.slice(-1);
    
          // calculate n-1 * multiplier
          var n_1multiplier = (+i-1)*multiplier
    
          // add f(n-1) and n_1multiplier
          var result = +fn_1+n_1multiplier;
          
          // assign the result to the array
          resultarray.push(result)
     
          }
        }
       
      // return the last value in the array
      return resultarray.slice(-1);
      
    }


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**Example data showing breakdown of calculations**

[![Screenshot][1]][1]


  [1]: https://i.sstatic.net/cCvVx.jpg