Here's the program in Python:
def main():
print("Please enter an even number for n:")
number = int(input())
if number % 2:
print("Wrong input!")
else:
answer = sum(range(2, number + 1, 2))
print(" + ".join( str(x) for x in range(2, number + 1, 2) ), "=", answer)
if __name__ == '__main__':
main()