 # Python Program to Find Sum of Series (1+(1+2)+(1+2+3)+…till N)

In the previous article, we have discussed Python Program to Swap Upper Diagonal Elements with Lower Diagonal Elements of Matrix.

Given a number N and the task is to find the sum of the given series (1+(1+2)+(1+2+3)+…till N) for the given number in Python.

Examples:

Example1:

Input:

Given Number = 25

Output:

The total sum of the series till the given number { 25 } =  2925

Example2:

Input:

Given Number = 18

Output:

The total sum of the series till the given number { 18 } =  1140

## Program to Find Sum of Series (1+(1+2)+(1+2+3)+…till N) in Python

Below are the ways to find the sum of the given series (1+(1+2)+(1+2+3)+…till N) for the given number in Python

### Method #1: Using While Loop (Static Input)

Approach:

• Give the number N as static input and store it in a variable.
• Take a variable say resltsum which gives the sum of the given series till N and initialize its value to 0.
• Take another variable say k and initialize its value with 1.
• Loop until the value of k is less than or equal to the given number using the while loop.
• Inside the loop, iterate from 1 to the value of k using the for loop.
• Add the iterator value to the above-initialized resltsum and store it in the same variable resltsum.
• Increment the value of k by 1 outside the for loop.
• Print the resltsum value which is the result of the series till the given Number N.
• The Exit of the Program.

Below is the implementation:

# Give the number N as static input and store it in a variable.
gvn_numb = 25
# Take a variable say resltsum which gives the sum of the given series till N and
# initialize its value to 0.
resltsum = 0
# Take another variable say k and initialize its value with 1.
k = 1
# Loop until the value of k is less than or equal to the given number using the while loop.
while(k <= gvn_numb):
# Inside the loop, iterate from 1 to the value of k using the for loop.
for itr in range(1, k+1):
# Add the iterator value to the above-initialized resltsum and store it in the same
# variable resltsum.
resltsum += itr
# Increment the value of k by 1 outside the for loop.
k += 1
# Print the resltsum value which is the result of the series till the given Number N.
print(
"The total sum of the series till the given number {", gvn_numb, "} = ", resltsum)


Output:

The total sum of the series till the given number { 25 } =  2925

### Method #2: Using While loop (User Input)

Approach:

• Give the number N as user input using the int(input()) function and store it in a variable.
• Take a variable say resltsum which gives the sum of the given series till N and initialize its value to 0.
• Take another variable say k and initialize its value with 1.
• Loop until the value of k is less than or equal to the given number using the while loop.
• Inside the loop, iterate from 1 to the value of k using the for loop.
• Add the iterator value to the above-initialized resltsum and store it in the same variable resltsum.
• Increment the value of k by 1 outside the for loop.
• Print the resltsum value which is the result of the series till the given Number N.
• The Exit of the Program.

Below is the implementation:

# Give the number N as user input using the int(input()) function and
# store it in a variable.
gvn_numb = int(input("Enter some Random Number = "))
# Take a variable say resltsum which gives the sum of the given series till N and
# initialize its value to 0.
resltsum = 0
# Take another variable say k and initialize its value with 1.
k = 1
# Loop until the value of k is less than or equal to the given number using the while loop.
while(k <= gvn_numb):
# Inside the loop, iterate from 1 to the value of k using the for loop.
for itr in range(1, k+1):
# Add the iterator value to the above-initialized resltsum and store it in the same
# variable resltsum.
resltsum += itr
# Increment the value of k by 1 outside the for loop.
k += 1
# Print the resltsum value which is the result of the series till the given Number N.
print(
"The total sum of the series till the given number {", gvn_numb, "} = ", resltsum)


Output:

Enter some Random Number = 18
The total sum of the series till the given number { 18 } = 1140

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