# A324853 (b-file synthesized from sequence entry) 0 1 1 2 2 6 3 30 4 330 5 4290 6 60060 7 1021020 8 29609580 9 917896980 10 33962188260 11 1290563153880 12 52913089309080 13 2275262840290440 14 106937353493650680 15 6309303856125390120 16 422723358360401138040 17 30013358443588480800840 18 2190975166381959098461320