the first 3 numbers of each line are memory addresses. the last number is a value stored in the array.
i won't get into the details, but a[0] points to 1245008 or a[0][0], which points to 1245008 or a[0][0][0] or the value 2. the address of "a" is also 1245008.
if you want to get down in there and study it, add the loop below
Code:
int a[2][3][2] = {{{2,4},{7,8},{3,4}},{{2,2},{2,3},{3,4}}};
printf("%u %u %u %d \n",a,*a,**a,***a);
printf("%u %u %u %d \n",a+1,*a+1,**a+1,***a+1);
for(int i = 0; i < 2; i++)
for(int j = 0; j < 3; j++)
for(int k = 0; k < 2; k++)
{
printf("The memory location %u holds the value %d (a[%d][%d][%d]) \n",
&a[i][j][k], a[i][j][k], i,j,k);
}