custom relation

Array ( [0] => 13730 [1] => 13733 [2] => 13734 [3] => 17121 [4] => 17462 [5] => 17577 [6] => 18394 [7] => 18994 [8] => 19632 [9] => 20179 [10] => 20211 [11] => 21029 [12] => 22119 [13] => 22120 [14] => 22217 [15] => 22864 [16] => 23320 [17] => 23352 [18] => 23395 [19] => 23397 [20] => 2428643 )