#include <stdio.h>
#include <inttypes.h>

#define prog_uchar uint8_t
#define PROGMEM


const prog_uchar lookupTable[3][4] PROGMEM =
{
   {7, 2, 5, 25},    // x[0][0..3]
   {2, 7, 3, 2},     // x[1][0..3]
   {1, 1, 23, 2}     // x[2][0..3]
};

int main() {
    printf("x[0][3]=%d\n", lookupTable[0][3]);

    exit(0);
}

x[0][3]=25