# A023943 (b-file synthesized from sequence entry) 0 1 1 0 2 27720 3 1272320 4 19707450 5 163430400 6 927305904 7 3995658240 8 14261752680 9 43493359616 10 118805241072 11 292653344256 12 671496501200 13 1430857236480 14 2904257385888 15 5571801102336 16 10326899016378 17 18297213419520