# A308499 (b-file synthesized from sequence entry) 0 0 1 1 2 3 3 10 4 34 5 104 6 200 7 -400 8 -2800 9 85120 10 2163840 11 30240000 12 285331200 13 1247769600 14 -15759744000 15 -392840448000 16 -1587505920000 17 123384188928000 18 4345827053568000 19 82159404687360000 20 749393890172928000 21 -10215518583029760000 22 -570363673124044800000 23 -9916595355495628800000