Number of fixed hexagonal polyominoes with n cells and tree-like structure.

A066331

Number of fixed hexagonal polyominoes with n cells and tree-like structure.

Terms

    a(0) =1a(1) =3a(2) =9a(3) =29a(4) =99a(5) =348a(6) =1260a(7) =4644a(8) =17382a(9) =65822a(10) =251655a(11) =969819a(12) =3762517a(13) =14680890a(14) =57567228a(15) =226712655a(16) =896252850a(17) =3555116583a(18) =14144563158

External references