256 128 etc

half.php

<?php

$number = 256;
$arr = [];

while($number > 0) {
  $arr[] = $number;
  $number = $number >> 1;
}

foreach (array_chunk($arr, 3) as $num) {
  echo "{$num[0]} | {$num[1]} | {$num[2]} \n";
}