Dirty recursive doubling triangle in PHP

doublingTriangle

<?php

echo "<center>";
doublingTriangle(1, 128);
echo "</center>";

function doublingTriangle($currentNumber = 1, $goalNumber = 10){
  if($currentNumber <= $goalNumber){
		if($currentNumber <= 1){
			echo $currentNumber . "<br>";
			doublingTriangle($currentNumber * 2, $goalNumber);
		} else {
			$middle = $currentNumber % 2 == 0 ? $currentNumber : doublingTriangle($currentNumber - 1, $goalNumber);
			$sides = str_repeat((string)1, $middle / 2);
			echo $sides . $middle . $sides . "<br>";
			doublingTriangle($middle * 2, $goalNumber);
		}
	}
}

Self correcting & recursive