# A365978 (b-file synthesized from sequence entry) 0 1 1 0 2 1 3 0 4 6 5 24 6 90 7 1008 8 7560 9 54432 10 712152 11 7620480 12 81130896 13 1266632640 14 17587441872 15 246734377344 16 4527397929600 17 77238618702336 18 1340945212763520 19 28407941067018240 20 574640938744314624 21 11868502219930137600 22 285787326567523173120