How do I do this program?

Projects Programming
10

I probably butchered this but here's the code anyway:

int x=0;
int buttonState;
void setup() {
  Serial.begin(9600);
  pinMode(7, INPUT_PULLUP);
    buttonState=digitalRead(7);
}
void loop() {
  if((buttonState==LOW)&&(x<=4)){
    Serial.print(2 << x);
    Serial.print(x, DEC)
    Serial.println(x, BIN);
  }
  x=x+1;
}