# A013250 (b-file synthesized from sequence entry) 0 1 1 0 2 0 3 0 4 -3 5 40 6 -250 7 840 8 -4515 9 87120 10 -949500 11 4360400 12 -24799775 13 1013539800 14 -16719504750 15 82697979000 16 -246429558375 17 40173677908000 18 -928344422395000 19 3990578889492000 20 32523853181113125