# A137437 (b-file synthesized from sequence entry) 1 1 2 0 3 0 4 0 5 -2 6 0 7 6 8 0 9 -24 10 0 11 120 12 40 13 0 14 -720 15 -420 16 0 17 5040 18 3948 19 0 20 -40320 21 -38304 22 -2240 23 0 24 362880 25 396576 26 50400