Number of polyominoes with n cells that have the symmetry group D_8.

Terms

a(0) =1a(1) =1a(2) =0a(3) =0a(4) =1a(5) =1a(6) =0a(7) =0a(8) =1a(9) =2a(10) =0a(11) =0a(12) =3a(13) =2a(14) =0a(15) =0a(16) =5a(17) =4a(18) =0a(19) =0a(20) =12a(21) =7a(22) =0a(23) =0a(24) =20a(25) =11a(26) =0a(27) =0a(28) =45a(29) =20