Low-temperature partition function expansion for hexagonal lattice (Potts model, q=4).

Terms

a(0) =1a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =3a(7) =0a(8) =0a(9) =0a(10) =9a(11) =18a(12) =-21a(13) =0a(14) =72a(15) =120a(16) =-45a(17) =-342a(18) =825a(19) =1296a(20) =-630a(21) =-2832a(22) =3411a(23) =21258a(24) =-6624a(25) =-40446a(26) =31338a(27) =209676a(28) =97677a(29) =-665712