<?php
error_reporting(-1);
$total = 15;
$skip  = 5;
$array = array();
$char = 0;

$array = range(1, $total);
while (count($array) >= $skip) {
foreach ($array as $key => $value) { 
	$char += 1;
	if ($char == $skip) {
		unset($array[$key]);
		$char = 0;
	}
}
}
var_dump($array);