Number of fixed polyominoes with n cells that have a horizontal axis of symmetry that passes through the centers of cells.

A346799

Number of fixed polyominoes with n cells that have a horizontal axis of symmetry that passes through the centers of cells.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =3a(4) =7a(5) =10a(6) =24a(7) =36a(8) =86a(9) =133a(10) =314a(11) =499a(12) =1164a(13) =1888a(14) =4366a(15) =7192a(16) =16522a(17) =27548a(18) =62954a(19) =106004a(20) =241203a(21) =409492a(22) =928376a(23) =1587151a(24) =3586999a(25) =6169400a(26) =13904736a(27) =24041597a(28) =54053950a(29) =93896826

External references