Transferring values from a char array to an integer array in C programming

I am having the following problem. I have created a char array which represents a series of characters and numbers - this was designed to model a string read or got from a text file. I wish to then search this string using the "search" function defined below, pulling out only the numbers before 'H' and assigning to a separately defined integer array. I find when I use gdb, this function works fine. However, only part of the array is ever returned - the first 8 elements to be exact. Would anyone please be able to explain why this is from looking at the code below?

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

void search(char buffer[], int size, int array[]);

int main (void)
{
    char buffer[1000];
    memset(buffer, 0, sizeof(buffer)); 

    buffer[0] = 2;
    buffer[1] = 'H';
    buffer[2] = 3;
    buffer[3] = 'H';  
    buffer[4] = 6;
    buffer[5] = 'H'; 
    buffer[6] = 4; 
    buffer[7] = 'H'; 
    buffer[8] = 6; 
    buffer[9] = 'H';
    buffer[10] = 7;
    buffer[11] = 'H';
    buffer[12] = 11;
    buffer[13] = 'H';
    buffer[14] = 12;
    buffer[15] = 'H';
    buffer[16] = 17;
    buffer[17] = 'H'; 

    int* array ;    
    array = malloc(sizeof(buffer) * sizeof(int));  

    search(buffer, sizeof(buffer), array); 

    for(int i = 0, n = sizeof(array); i < n; i++)
    {
        printf("array[%d] = %d\n", i, array[i]);
    } 

    free(array); 
}

void search(char buffer[], int size, int array[])
{
    int position = 0;

    for (int i = 0; i < size; i++)
    {
        if(buffer[i] == 'H')
        {
            *(array + position) = buffer[i-1];
            position++;
        }
    }       
}

The compiler outputs the following:

array[0] = 2
array[1] = 3
array[2] = 6
array[3] = 4
array[4] = 6
array[5] = 7
array[6] = 11
array[7] = 12

which as can be seen is missing the ninth position in the array - value 17. In fact, if I fgets into a buffer a much bigger set of numbers and 'H's, I am always returned an array of size 8. Why is this? Any help would be much appreciated.