How to display numbers vertically 1 to 20 using php - php

Question

this is the sample logic i want to use.
1 6 11 16
2 7 12 17
3 8 13 18
4 9 14 19
5 10 15 20
this is my sample code. i'm just getting the logic from numbers so i can use to to what i want to display. thank you in advance to those who can help me.
<?php
$counter = 0;
$columnctr = 0;
for ($x = 0; $x <= 4; $x++) :?>
<tr>
<?php for ($j = 0; $j <= 17; $j++) :?>
<?php if($counter == $x) : ?>
<?php
$i = 0;
?>
<?php foreach ($iterator as $val) :?>
<?php if($x == $i) : ?>
<td>
<?php if($val == "meron") : ?>
<span class="circle-blue">
</span>
<?php $counter++;?>
<?php else : ?>
<span class="circle-red">
</span>
<?php $counter++;?>
<?php endif; ?>
</td>
<?php endif; ?>
<?php $i++;?>
<?php endforeach;?>
<?php else : ?>
<td>
</td>
<?php endif; ?>
<?php endfor;?>
</tr>

Answer 1

$total = 20;
$totalRow = 5;
$totalCol = ceil($total/$totalRow);
echo '<pre>';
for($x = 1; $x <= $totalRow; $x++){
for($y=1; $y <= $totalCol; $y++){
$number = $x + (($y -1) * $totalRow);
// don't print extra number for last column, check for $total = 21 or 22
if($number <= $total)
echo $number. ' ';
}
echo PHP_EOL;
}

Answer 2

for($i=1;$i<=5;$i++):
$f = 0;
for($j=$i;$j < ($i+4) ; $j++ ):
if($f == 0):
echo $j." ";
$p = $j;
else:
echo $p = ($p + 5)." ";
endif;
$f = 1;
endfor;
echo "<br/>";
endfor;