Print Fibo Recur and linked list looped

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


typedef struct node{
        int n;
        struct node* _next;
} Node;


void fibo_o(Node *prev, Node *first, int n){
        Node *new_node = malloc(sizeof(Node));

        if(n==0){
                prev->_next->_next=first;
                return;
        }
        new_node->n = prev->n+prev->_next->n;
        prev->_next->_next=new_node;

        fibo_o(prev->_next, first, n-1);
        printf("%d,", new_node->n);

}

void fibo(float n){
        Node *second = malloc(sizeof(Node));
        Node *first = malloc(sizeof(Node));
        if(((float) n) != ((int) n)  || n<0){
                printf("Invalid number\n");
                return;
        }
        if(n==0){
                first->_next=first;
                printf("1\n");
                return;
        }
        first->n=second->n=1;
        first->_next = second;
        fibo_o(first, first, (int)(n-1));
        printf("1,1\n");

}