# A093842 (b-file synthesized from sequence entry) 1 2 2 8 3 24 4 264 5 1320 6 22440 7 157080 8 2356200 9 18849600 10 339292800 11 3053635200 12 174057206400 13 2262743683200 14 61094079446400 15 855317112249600 16 25659513367488000 17 821104427759616000 18 13137670844153856000