# A085081 (b-file synthesized from sequence entry) 1 1 2 2 3 3 4 4 5 1680 6 2162160 7 586051200 8 5967561600 9 1220096908800 10 33371339479827148800 11 10221346459144248675287040000 12 1065516759202418135010355181075171069914644480000000