# A012533 (b-file synthesized from sequence entry) 0 1 1 2 2 20 3 440 4 17488 5 1122208 6 108352576 7 14910020736 8 2796629584128 9 688871838614016 10 216055818814010368 11 84109725396766971904 12 39796388326939272466432 13 22489039556700087459291136 14 14957634359368597313889648640 15 11564305283318420635370333569024