Percolation series for directed hexagonal lattice.

Terms

a(0) =1a(1) =0a(2) =0a(3) =-1a(4) =-2a(5) =-5a(6) =-10a(7) =-20a(8) =-41a(9) =-86a(10) =-182a(11) =-393a(12) =-853a(13) =-1887a(14) =-4208a(15) =-9445a(16) =-21350a(17) =-48612a(18) =-111307a(19) =-255236a(20) =-590543a(21) =-1362919a(22) =-3182137a(23) =-7362611a(24) =-17377129a(25) =-40125851a(26) =-96106251a(27) =-219681825a(28) =-539266908a(29) =-1200140540