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

A326368

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

Terms

    a(0) =0a(1) =0a(2) =18a(3) =434a(4) =2814a(5) =11127a(6) =33365a(7) =83568a(8) =184254a(9) =369254a(10) =686952a(11) =1203930a(12) =2009018a(13) =3217749a(14) =4977219a(15) =7471352a(16) =10926570a(17) =15617868a(18) =21875294a(19) =30090834a(20) =40725702a(21) =54318035a(22) =71490993a(23) =92961264a(24) =119547974a(25) =152182002a(26) =191915700a(27) =239933018a(28) =297560034a(29) =366275889

External references