How do I display a Random number generated in a TextView?

I am generating random flashes of a button and I want to know what exact number is being chosen each time so I can eventually add them to an ArrayList for a project I am undergoing.

TextView randomTextView;
Random r = new Random();

private void sequenceFunction() {
    //Change Alpha from Fully Visible to Invisible
    final Animation animation = new AlphaAnimation(1, 0);
    //Duration - A Second
    animation.setDuration(1000);
    //Animation Rate
    animation.setInterpolator(new LinearInterpolator());
    animation.setStartOffset(250);
    animation.setDuration(250);
    //Repeat Animation
    animation.setRepeatCount(r.nextInt(10));

    // Reverse animation at the end so the button will fade back in
    animation.setRepeatMode(Animation.REVERSE);

    //Button 1 Flashes
    final Button btn = (Button) findViewById(R.id.button);
    btn.startAnimation(animation);
    btn.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(final View view) {
            view.clearAnimation();
        }
    });
}

I want to display the result of what ever random number has been generated via the randomTextView TextView. This part is critical so that I know that the random function is working as it is supposed to. I have already tried

randomTextView.setText(r.nextInt(10));

However it didn't like it. Any ideas on how to get the random number selected would be greatly appreciated ?