Triangular polyominoes (or polyiamonds) with n cells at most (turning over is allowed, holes are allowed, must be connected along edges).

A130867

Triangular polyominoes (or polyiamonds) with n cells at most (turning over is allowed, holes are allowed, must be connected along edges).

Terms

    a(0) =1a(1) =2a(2) =3a(3) =6a(4) =10a(5) =22a(6) =46a(7) =112a(8) =272a(9) =720a(10) =1906a(11) =5240a(12) =14475a(13) =40641a(14) =114624a(15) =325921a(16) =930028a(17) =2666356a(18) =7666949a(19) =22115933a(20) =63951671a(21) =185370931a(22) =538416222a(23) =1566868939a(24) =4567669566a(25) =13336886288a(26) =38998848186a(27) =114194014853

External references