# A097173 (b-file synthesized from sequence entry) 1 0 2 2 3 0 4 48 5 120 6 4560 7 35700 8 1048992 9 15514128 10 456726240 11 10073339100 12 323266492560 13 9361060088952 14 336767513038320 15 11913610172869860 16 482920107426039360 17 19998225191360977440 18 909512248720724321472