Fibo, Tribo and Tetra nacci number, Lucas number in PHP

nacci.php

<?php

const CALC_LIMIT = 1000;

// fibo
var_dump(implode(', ', nacci(CALC_LIMIT, [0, 1])));

// tribo
var_dump(implode(', ', nacci(CALC_LIMIT, [0, 0, 1])));

// tetra
var_dump(implode(', ', nacci(CALC_LIMIT, [0, 0, 0, 1])));

// lucas
var_dump(implode(', ', nacci(CALC_LIMIT, [2, 1])));

function nacci($max, $seq) {
    $seq_len = count($seq);
    while ($max >= ($current = array_sum(array_slice($seq, count($seq) - $seq_len, $seq_len)))) {
        $seq[] = $current;
    }
    return $seq;
}

?>