# A067655 (b-file synthesized from sequence entry) 1 1 2 1 3 3 4 3 5 15 6 45 7 315 8 315 9 2835 10 14175 11 155925 12 467775 13 6081075 14 3869775 15 638512875 16 638512875 17 10854718875 18 8881133625 19 1856156927625 20 9280784638125 21 194896477400625 22 2143861251406875 23 2595200462229375