(a),(b): 1770 triples {0,a,b} with b <= 60: phi_1 != 1/4 in 0 cases; closed form for phi_2 fails in 0 cases
(c) phi_1({0,1,2,3}) - 1/5 = 1/270 ; phi_1({0,1,2,4}) - 1/5 = -7/2160
(c) 4-sets with min 0 and max <= 64: 41664; phi_1 < 1/5: 21630; phi_1 = 1/5: 0; classes 17916
