Welcome to the daily solving of our PROBLEM OF THE DAY with Karan Mashru. We will discuss the entire problem step-by-step and work towards developing an optimized solution. This will not only help you brush up on your concepts of Recursion but also build up problem-solving skills.

In this problem, we are given A function F is defined as follows F(n)= (1) +(2*3) + (4*5*6) ... upto n terms (look at the examples for better clarity). Given an integer n, determine the F(n).

Note: As the answer can be very large, return the answer modulo 109+7.

Example :

Input: n = 5
Output: 365527

Explanation: 
F(5) = 1 + 2*3 + 4*5*6 + 7*8*9*10 + 11*12*13*14*15 = 365527.

Give the problem a try before going through the video. All the best!!!
Problem Link: https://www.geeksforgeeks.org/problems/recursive-sequence1611/1