Answer to Question #230030 in Python for Roti

Question

Write a code to find out the sum of the sequence 2 -4 6 -8 10 -12... While the last value will be determined from input. Use a loop to solve the problem.

Answer 1

N = int(input("Enter the number of elements in series: "))
Sum = 0
s=""
for r in range(0,N):
    u = (2*r+2)*((-1)**r)
    if(u>0): s=s+"+"+str(u)
    else:    s = s+str(u)
    Sum = Sum + u


print("Sum of series: ",s," = ",Sum)