# A294512 (b-file synthesized from sequence entry) 0 1 1 8 2 168 3 420 4 5460 5 14560 6 276640 7 3043040 8 136936800 9 136936800 10 4245040800 11 72165693600 12 2670130663200 13 2670130663200 14 114815618517600 15 1320379612952400 16 9242657290666800 17 3080885763555600 18 280080523959600 19 8122335194828400 20 165154148961510800 21 14533565108612950400 22 973748862277067676800