Number of tilings of an equilateral triangle of side length n with unit triangles (of side length 1) and exactly two unit "lozenges" or "diamonds" (also of side length 1).

A326367

Number of tilings of an equilateral triangle of side length n with unit triangles (of side length 1) and exactly two unit "lozenges" or "diamonds" (also of side length 1).

Terms

    a(0) =0a(1) =0a(2) =24a(3) =126a(4) =387a(5) =915a(6) =1845a(7) =3339a(8) =5586a(9) =8802a(10) =13230a(11) =19140a(12) =26829a(13) =36621a(14) =48867a(15) =63945a(16) =82260a(17) =104244a(18) =130356a(19) =161082a(20) =196935a(21) =238455a(22) =286209a(23) =340791a(24) =402822a(25) =472950a(26) =551850a(27) =640224a(28) =738801a(29) =848337

External references