# A358491 (b-file synthesized from sequence entry) 1 1 2 1 3 5 4 10 5 74 6 216 7 2316 8 8688 9 128880 10 581760 11 11406240 12 59667840 13 1482693120 14 8782905600 15 266800262400 16 1762116249600 17 63536485017600 18 462613126348800 19 19342202181120000 20 153884245616640000 21 7325057766297600000