# A052625 (b-file synthesized from sequence entry) 0 1 1 0 2 0 3 6 4 48 5 360 6 3600 7 45360 8 645120 9 10160640 10 177811200 11 3432844800 12 72329241600 13 1650160512000 14 40537905408000 15 1067062284288000 16 29961435119616000 17 893842506805248000 18 28234468042260480000