# A013206 (b-file synthesized from sequence entry) 0 0 1 1 2 -2 3 6 4 -20 5 120 6 -872 7 7056 8 -68000 9 758400 10 -9460352 11 130918656 12 -1995073280 13 33173038080 14 -597457144832 15 11587651270656 16 -240799724687360 17 5337660866396160 18 -125711013390221312