UART does not do what I want

But it does not give the values I programmed? (see attachment). I repeated it a couple of times but everytime a couple of bits seem off.

Do you want that the Serial Monitor should show the values which you have exactly stored into the array members? If so, execute the following codes:

void setup()
{
  Serial.begin(9600);
  byte buf[8];
  buf[0] = 0;
  buf[1] = 170;
  buf[2] = 0;
  buf[3] = 3;
  buf[4] = 0;
  buf[5] = 2;
  buf[6] = 0;
  buf[7] = 251;

  for (int i = 0; i < sizeof(buf); i++)
  {
    Serial.println(buf[i]);
  }
}

void loop() 
{

}