# A009645 (b-file synthesized from sequence entry) 0 0 1 0 2 2 3 -6 4 30 5 -180 6 1324 7 -11424 8 113376 9 -1271232 10 15889280 11 -218989760 12 3298513600 13 -53897151360 14 949389619840 15 -17931842342400 16 361486218406400 17 -7746121344512000 18 175813073606092800 19 -4213227577441536000