JavaScript is multiplying by 2 instead of adding by 1 [duplicate]

I have a piece of code that has a text with an id, a button with a function to go to JavaScript to add a number every 10 seconds my problem is instead of adding 1 number it multiplies by 2

This is what I tried

function autoclick() {
  var x = Math.floor((Math.random() + 1) + 0, ),
    el = document.getElementById('test'),
    val = parseInt(el.innerHTML, 10);
  el.innerHTML = val + x;
  var t = setInterval(autoclick, 1000);
}

<p id="test">0</p>
<button onclick="autoclick()">autoclick</button>