Online PHP editor | refs for jNueF

<?php function gap($g, $m, $n) { foreach (range($m, $n) as $num) { if ($isPrime = isPrime($num) && isset($firstPrime) && $num - $firstPrime == $g) { return [$firstPrime, $num]; } elseif ($isPrime) { $firstPrime = $num; } } return null; } function isPrime($num) { for ($n = 2; ($div = $num/$n) > $n; $n++) { if (is_int($div)) { return false; } } return true; } var_dump(gap(2, 100, 110));