Sum of odd numbers code help

Question

calculates and returns the sum of all the odd numbers from 1 to x.?
this is what i have so far:
for (count = 1; i = x; i++)
sum = 0;
count + 2;
sum = count
i = i + 2
when i compile, i get an error because count + 2; is not a statement. why? Your help is greatly appreciated.

Answer 1

Try this out:
import static java.lang.System.out;
public class InnerSum {
public static int sum(int a1, int an) {
int num_terms = an / 2 + 1;
return (num_terms*(2*a1 + ((num_terms-1)*2)))/2;
public static void main(String[] args)
out.println(sum(1, 5));
out.println(sum(1, 9));
out.println(sum(1, 13));
out.println(sum(1, 15));
     }