define("MAX_GEN",5);

function detail($number) {
    $d = mysql_query("select * from table where number = '$number'");
    if(mysql_num_rows($d) == 0) {
        $p[name] = "N/A";
        $p[number] = "N/A";
        $p[m_number] = "N/A";
        $p[f_number] = "N/A";
    }
    else $p = mysql_fetch_assoc($d);
    return $p;
}

function gen($number, $generation = 0, $out) {

    if ($generation >= MAX_GEN) {
        return false;
    }

    $record = detail($number);

    if ($generation == 0) $out[0][] = $record; // first man

    $generation++; // next generation

    if (!$out[$generation] && ($generation != MAX_GEN)) $out[$generation] = array();

    $x_mother = gen($record[m_number], $generation ); // continue with mother
    $x_father = gen($record[f_number], $generation ); // continue with father

    if ($out[$generation]) {
        $out[$generation][] = $x_mother;
        $out[$generation][] = $x_father;
    }
    return $out;
}