"Programming is not a zero-sum game..." // John Carmack
A sequence with same common difference is known as arithmetic sequence. The first term of sequence is a and common difference is d. The series looks like a, a + d, a + 2d, a + 3d, . . . How many terms to go is n.
Arithmetic sum formula is shown below - this is all domain knowledge required for this exercise.
Write a CC for finding the sum of n-terms of an arithmetic sequence requiring these three parameters a,d,n mentioned above from user input, let those be integers. Your task is to write it using range function to sum these parameters, but in addition write a verification code using math functions according to given formula.