Bond percolation series for square lattice.

Terms

a(0) =1a(1) =2a(2) =4a(3) =8a(4) =15a(5) =28a(6) =50a(7) =90a(8) =156a(9) =274a(10) =466a(11) =804a(12) =1348a(13) =2300a(14) =3804a(15) =6450a(16) =10547a(17) =17784a(18) =28826a(19) =48464a(20) =77689a(21) =130868a(22) =207308a(23) =350014a(24) =548271a(25) =931584a(26) =1433966a(27) =2469368a(28) =3725257a(29) =6510384