# A366942 (b-file synthesized from sequence entry) 0 1 1 1 2 6 3 48 4 408 5 5040 6 72000 7 1184400 8 22619520 9 482993280 10 11459750400 11 299495750400 12 8531976499200 13 263353163673600 14 8754879893760000 15 311808414677760000 16 11845876873678848000 17 478163414336864256000 18 20436460099541950464000 19 921972301728418676736000