# A280982 (b-file synthesized from sequence entry) 1 1 2 1 3 2 4 6 5 54 6 486 7 9720 8 204120 9 6531840 10 241678080 11 13050616320 12 652530816000 13 50244872832000 14 4069834699392000 15 390704131141632000 16 41023933769871360000 17 5538231058932633600000 18 731046499779107635200000 19 124277904962448297984000000