# A220027 (b-file synthesized from sequence entry) 0 1 1 1 2 2 3 6 4 12 5 60 6 180 7 1260 8 5040 9 5040 10 25200 11 277200 12 2494800 13 32432400 14 227026800 15 227026800 16 3632428800 17 61751289600 18 61751289600 19 1173274502400 20 29331862560000 21 29331862560000 22 322650488160000 23 7420961227680000 24 601097859442080000 25 601097859442080000