1+2+3+.....+n.c

#include<stdio.h>
int main ()
{
    int i,n;

    printf("The value of n: ");
    scanf("%d",&n);

    for(i=1;i<=n;i++)
    {
        if(i%2==0)
            printf("%d is even number\n",i);

        else
            printf("%d is odd number\n",i);
    }

    return 0;
}


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Output--

The value of n: 10
1 is odd number
2 is even number
3 is odd number
4 is even number
5 is odd number
6 is even number
7 is odd number
8 is even number
9 is odd number
10 is even number