# A012704 (b-file synthesized from sequence entry) 0 0 1 0 2 2 3 -3 4 16 5 -50 6 248 7 -504 8 -1584 9 94536 10 -1222848 11 16675560 12 -150260640 13 1047505680 14 12037737840 15 -574519410360 16 16243532175360 17 -341049918471360 18 6341386354483200 19 -86729688288097920 20 452837960565661440 21 31661940854577882240 22 -1682428415293547953920