OS01.c

#include<stdio.h>
#include<stdlib.h>

int main(int argc, char **argv[])
{
    int i, uInp;
    if(argc==2)
    {
        uInp = atoi(argv[1]);

        if(uInp<0)
        {
            printf("\n Negative integer is not allow.\n");
            return 1;
        }
        int sn[uInp];
        for(i=0; i<uInp; i++)
        {
            if(i == 0 || i == 1)
                sn[i]=1;
            else if(i == 2)
                sn[i]=2;
            else if(i == 3)
                sn[i]=3;
            else if((i%3) == 0)
                sn[i]=sn[i-1];
            else
                sn[i]=(sn[i-2]*2)-1;
            printf("%d  ", sn[i]);
        }
    }else{
        printf("\n This program requires least one argument.\n");
        return 1;
    }
    return 0;
}