Z/5 (exact over Q(zeta_5)): H_A=[1, 5, 3, 1, 1] H_B=[1, 5, 22, 96, 407] H_A(t)H_B(-t)=[1, 0, 0, 0, -11]
Z/7 (exact over Q(zeta_7)): H_A=[1, 7, 4, 1] H_B=[1, 7, 45, 286] H_A(t)H_B(-t)=[1, 0, 0, 2]
