Question

Write a program in Java to find the sum of the following series
S= 2
1 + 42 + 63 +....................n terms
Take necessary input from the user.

Answer 1

Answer:

Given the value of the n. You have to find the sum of the series where the nth term of the sequence is given by:

Tn = n2 – ( n – 1 )2

Examples :

Input : 3

Output : 9

Explanation: So here the tern of the sequence upto n = 3 are:

1, 3, 5 And hence the required sum is = 1 + 3 + 5 = 9

Input : 6

Output : 36

Simple Approach

Just use a loop and calculate the sum of each term and print the sum.

// CPP program to find summation of series

#include <bits/stdc++.h>

using namespace std;

int summingSeries(long n)

{

// use of loop to calculate

// sum of each term

int S = 0;

for (int i = 1; i <= n; i++)

S += i * i - (i - 1) * (i - 1);

return S;

}

// Driver Code

int main()

{

int n = 100;

cout << "The sum of n term is: "

<< summingSeries(n) << endl;

return 0;

}