# A137737 (b-file synthesized from sequence entry) 1 0 2 1 3 0 4 30 5 0 6 13560 7 0 8 27785520 9 0 10 162030637440 11 0 12 2156625389318400 13 0 14 56857271240920550400 15 0 16 2686506065987036477184000 17 0 18 211180868835057744408834048000 19 0 20 26072812428113877344085395644416000 21 0