# A352059 (b-file synthesized from sequence entry) 1 0 2 1 3 2 4 6 5 24 6 180 7 720 8 840 9 20160 10 378000 11 3628800 12 6985440 13 479001600 14 6235669440 15 47221574400 16 259459200 17 20922789888000 18 2972883513600 19 6402373705728000 20 20274518622758400 21 1219830034655232000 22 51090956251003468800 23 1124000727777607680000