```
# PURPOSE: to calculate the sum of the first (n) odd counting numbers
#
# INPUT(S): the number (n) which will be the last number added to the sum
#
# OUTPUT(S): the sum of the first (n) counting numbers
#
# EXAMPLES: input: 23 ; output: 144
# input: 15 ; output: 64
#
################################################################################
import math
def sums(n):
total = 0
for i in range(0, n + 1, 1):
total += i
return total
def main():
n = input('Enter a number: ')
s = sums(n)
print 'The sum of the numbers is', s
while n <= 0:
print "Please Enter a positive number."
break
main()
```

the code in this program is actually to calculate just the sum of (n) counting numbers. what i'm trying to do is listed in the purpose and i know that the "sum= 1 +3+5 +7+...+2n -1" but i've tried numerous ways to figure out how to correctly modify the above code to print the right calculations of the sum. any type of help is welcome, thanks!