The re-factored fast solution to the project euler problem

peuler1_refactor.py

def func(n):
	n1 = ((n/3) - 1) if n%3  == 0 else (n/3)
	n2 = ((n/5) - 1) if n%5  == 0 else (n/5)
	n3 = ((n/15)- 1) if n%15 == 0 else (n/15)

	s1 = (n1*(n1+1))/2
	s2 = (n2*(n2+1))/2
	s3 = (n3*(n3+1))/2

	return (3*s1) + (5*s2) - (15*s3)

t = int(raw_input())

while t>0:
	n = int(raw_input())
	print func(n)
	t-=1