# A141055 (b-file synthesized from sequence entry) 0 -1 1 -2 2 -60 3 -120 4 -5040 5 -10080 6 -302400 7 -604800 8 -39916800 9 -79833600 10 -217945728000 11 -435891456000 12 -2615348736000 13 -5230697472000 14 -2667655710720000 15 -5335311421440000 16 -4257578514309120000 17 -8515157028618240000 18 -2810001819444019200000