[1,1,1,1,4,1,1,6,6,1,1,8,12,8,1,1,10,20,20,10,1,1, 12,30,40,30,12,1,1,14,42,70,70,42,14,1,1,16,56, 112,140,112,56,16,1,1,18,72,168,252,252,168,72,18, 1,1,20,90,240,420,504,420,240,90,20,1]