# A152710 (b-file synthesized from sequence entry) 1 1 2 2 3 6 4 24 5 120 6 720 7 5040 8 40320 9 362880 10 3456000 11 35759520 12 400628736 13 4789308672 14 61341750208 15 840540050688 16 12292652292672