1, 1, 2, 5, 14, 43, 140, 474, 1650, 5863, 21170, 77441, 286372, 1068790, 4020704, 15230470, 58044354, 222401745, 856235030, 3310615055, 12849946406, 50051007940, 195571906140, 766413504375, 3011469930300, 11862075827007, 46830440626612, 185271557066226