         delay(normal);
     }
     
-    for (int i = 0, j = sizeof(background); i < (sizeof(background) / 2); i++, j--) {
+    for (int i = 0, j = sizeof(background) - 1; i < (sizeof(background) / 2); i++, j--) {
         digitalWrite(background[i], PATTERN_ON);
         delay(none);
         digitalWrite(background[j], PATTERN_ON);


    delay(extended);

    for (int i = (sizeof(background) / 2) - 1, j = (sizeof(background) / 2); i >= 0; i--, j++) {
        digitalWrite(background[i], PATTERN_OFF);
        delay(none);
        digitalWrite(background[j], PATTERN_OFF);


    delay(normal);

    for (int i = 0; i < sizeof(letters); i++) {
        digitalWrite(letters[i], PATTERN_OFF);
        delay(none);
    }
