# A156102 (b-file synthesized from sequence entry) -1 1 0 1 1 5 2 10 3 70 4 440 5 4280 6 44560 7 575920 8 8224640 9 134583680 10 2422639360 11 48232203520 12 1044455459840 13 24541639470080 14 620471213148160 15 16815502865029120 16 485975291876311040 17 14924807659888148480 18 485281269068774440960 19 16656262639515411742720 20 601766641496428795658240