Can we solve this Arithmetic Problem using Python in a more efficient way?

Question

I've been thinking about making an Equation Solving program, starting off with some basic Equations first.

I have this Arithmetic progression problem here

Problem Statement: If the nth term of AP is 3n + 2 find the sum up to 15 terms

This is what I have tried,

n = 1
while n <= 15:
 ap = 3 * n + 2
 n += 1
print(ap)
#OUTPUT: 47

Is there a more efficient way to calculate these types of problems using python?

I'm thinking of handling bigger equations And the answer is not quite Correct

• mackorone: The more efficient way to perform this task is to come up with a closed-form solution to the problem - a formula for the summation - using math. What you wrote is already the best you can do with a naive approach.
• jackal: Why is there a loop here? print(3 * 15 + 2) would suffice.
• Ahmed AEK: if you are looking for very fast math and nothing else, then using C/C++ is much faster than python, but if you have some math that you must do fast in a python program, then consider using cython or numba to speed up the calculation.
• Kelly Bundy: Define "these types of problems".
• PSR: U could use lambda functions ?

Answer 1

If you want the sum of 3n+2 for 1<=n<=15 then:

print(sum(3*n+2 for n in range(1,16)))

Output:

390

Answer 2

you can use the closed formula for arithmetic sequence

def fn(n):
 return 3*(n*(n+1)//2) + 2*n

Answer 3

ap = 0
for n in range(1,16):
 ap += 3 * n + 2
print(ap)

• Jeremy Caney: Remember that Stack Overflow isn't just intended to solve the immediate problem, but also to help future readers find solutions to similar problems, which requires understanding the underlying code. This is especially important for members of our community who are beginners, and not familiar with the syntax. Given that, can you edit your answer to include an explanation of what you're doing and why you believe it is the best approach?