<?php
error_reporting(-1);
mb_internal_encoding('utf-8');

$total = 30;
$skip = 5;

$totalAr = array_fill(1, $total, 0);
$a = 1;
foreach ($totalAr as &$value){
    $value += $a;
    $a++;
}

$e = 0;
while(count($totalAr) >= $skip) {
    foreach ($totalAr as $k => $v) {
        $e++;
        if ($e == $skip) {
            unset($totalAr[$k]);
            $e = 0;
        }
    }
}

print "Чай пьют " . implode(', ', $totalAr);