# A012697 (b-file synthesized from sequence entry) 0 1 1 0 2 2 3 -3 4 28 5 -110 6 1058 7 -6804 8 75024 9 -664488 10 8456712 11 -94737720 12 1378535112 13 -18587872368 14 305610292752 15 -4802794952760 16 88232994448128 17 -1580181612876864 18 32119507894881216 19 -644756418530970624