# A002980 (b-file synthesized from sequence entry) 0 1 1 1 2 0 3 -1 4 24 5 121 6 -480 7 -4201 8 48384 9 478801 10 -4968960 11 -62871601 12 885586944 13 12996863881 14 -203910819840 15 -3476839930201 16 63397697224704 17 1221998040867361 18 -24917358603141120 19 -537278342731116001