Number of polyhexes with n cells that tile the plane by 180-degree rotation (Conway criterion).

A075211

Number of polyhexes with n cells that tile the plane by 180-degree rotation (Conway criterion).

Terms

    a(0) =1a(1) =1a(2) =3a(3) =7a(4) =21a(5) =75a(6) =256a(7) =929a(8) =3090a(9) =9235a(10) =21216a(11) =80463a(12) =138623a(13) =423595a(14) =1160355a(15) =2456117a(16) =4272856a(17) =15986299a(18) =21709209a(19) =75452662a(20) =156068738

External references