Number of polyominoes with n cells that tile the plane by 180-degree rotation (Conway criterion) but not by translation.

A075201

Number of polyominoes with n cells that tile the plane by 180-degree rotation (Conway criterion) but not by translation.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =3a(5) =11a(6) =60a(7) =199a(8) =748a(9) =2181a(10) =5391a(11) =17193a(12) =31881a(13) =85942a(14) =218760a(15) =430339a(16) =728315a(17) =2344106a(18) =3096983a(19) =9344528a(20) =17859116a(21) =31658109a(22) =49644736a(23) =172596719a(24) =228795554

External references