// forum dot arduino.cc/t/binary-counter-led-project-issue/1438696
// https <colon> //wokwi.com/projects/460881036579813377

const byte led0 = 10;
const byte led1 = 11;
const byte led2 = 12;
const byte led3 = 13;

void setup() {
  pinMode(led0, OUTPUT);
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
}

/*
  int numArray1[8] = {0,2,4,6,8,10,12,14};
  int numArray2[8] = {0,1,4,5,8,9,12,13};
  int numArray3[8] = {0,1,2,3,8,9,10,11};
  int numArray4[8] = {0,1,2,3,4,5,6,7};
*/

byte counter;

void loop() {
  delay(777);

  switch (counter) {
  case 0 :
  case 2 :
  case 4 :
  case 6 :
  case 8 :
  case 10 :
  case 12 :
  case 14 :
      digitalWrite(led0, LOW);
      break;

    default :
      digitalWrite(led0, HIGH);
  }

  switch (counter) {
  case 0 ... 1 :
  case 4 ... 5 :
  case 8 ... 9 :
  case 12 ... 13 :
    digitalWrite(led1, LOW);
    break;

  default :
      digitalWrite(led1, HIGH);
  }

  switch (counter) {
  case 0 ... 3 :
  case 8 ... 11 :
    digitalWrite(led2, LOW);
    break;

  default :
      digitalWrite(led2, HIGH);
  }

  switch (counter) {
  case 0 ... 7 :
    digitalWrite(led3, LOW);
    break;

  default :
      digitalWrite(led3, HIGH);
  }

  counter++;
  if (counter >= 16) counter = 0;
}