# A114310 (b-file synthesized from sequence entry) 1 1 2 1 3 6 4 108 5 2640 6 84600 7 3613680 8 203071680 9 14629870080 10 1316802614400 11 144849884256000 12 19120208432371200 13 2982752889071155200 14 542861032044198067200 15 114000816839126241024000 16 27360196043430269859840000 17 7441973323852870393823232000 18 2277243837099794643157389312000