Number of fixed hexagonal polyominoes with n cells that have a horizontal axis of symmetry that is a diagonal of at least one of the n cells.

A347258

Number of fixed hexagonal polyominoes with n cells that have a horizontal axis of symmetry that is a diagonal of at least one of the n cells.

Terms

    a(0) =1a(1) =0a(2) =3a(3) =1a(4) =10a(5) =5a(6) =40a(7) =23a(8) =169a(9) =107a(10) =741a(11) =499a(12) =3334a(13) =2349a(14) =15278a(15) =11141a(16) =71012a(17) =53198a(18) =333756a(19) =255553a(20) =1582885a(21) =1234059a(22) =7563365a(23) =5986757a(24) =36367445a(25) =29161696a(26) =175810059a(27) =142561190a(28) =853868747a(29) =699179932

External references