custom relation

Array ( [0] => 13730 [1] => 13733 [2] => 13734 [3] => 16596 [4] => 17003 [5] => 17121 [6] => 17462 [7] => 17577 [8] => 18994 [9] => 19632 [10] => 20179 [11] => 20211 [12] => 21029 [13] => 22217 [14] => 23320 [15] => 23352 [16] => 23395 [17] => 23397 [18] => 2428643 )