Your program is printing as expected, in terms that it should print the value of
n after every iteration, however you do have some errors in formatting your
printf statement. Specifically, you forgot to add in a newline after printing the number itself.
Here's a fixed version of your code:
int n = get_int("Enter An Integer: ");
if (n == 1)
// Don't forget your '\n'!
else if (n % 2 == 0)
n = n / 2;
// Same as n % 2 != 0, just some syntactic sugar!
else if (n % 2)
n= 3 * n + 1;
} while (n != 1);
// No need to return 0 within the do loop!