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


for ($i = 1; $i <= $total; $i++) {
    array_push($array, $i);
}

function counter($array, $skip, $total)
{
    $end = end($array);
    foreach ($array as $key => $value) {
        if ($value == $end) {
            $last = $key;
        }
        for ($i = 0; $i <= $total; $i++) {
            if ($key == ($skip + $skip * $i) - 1) {
                $char = $key;
                unset($array[($skip + $skip * $i) - 1]);
            }
        }
        $remain = $last - $char;
    }
    $array = array_values($array);
    $ar    = array();
    foreach ($array as $key => $value) {
        array_push($ar, $key + $remain);
    }
    if ($remain != 0) {
        $array = array_combine($ar, $array);
    }
    return $array;
}

while (count($array) >= $skip) {
    $array = counter($array, $skip, $total);
}
var_dump($array);