Percolation series for hexagonal lattice.

Terms

a(0) =1a(1) =0a(2) =0a(3) =-1a(4) =0a(5) =-3a(6) =1a(7) =-9a(8) =6a(9) =-29a(10) =27a(11) =-99a(12) =112a(13) =-351a(14) =450a(15) =-1275a(16) =1782a(17) =-4704a(18) =6998a(19) =-17531a(20) =27324a(21) =-65758a(22) =106211a(23) =-247669a(24) =411291a(25) =-935107a(26) =1587391a(27) =-3535398a(28) =6108103a(29) =-13373929