Triangle T(n, k) = Numbers of inequivalent (mod D_3) ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle with sides parallel to the grid. Triangle read by rows.
A243207
Triangle T(n, k) = Numbers of inequivalent (mod D_3) ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle with sides parallel to the grid. Triangle read by rows.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =3a(6) =1a(7) =3a(8) =10a(9) =20a(10) =25a(11) =11a(12) =3a(13) =4a(14) =22a(15) =77a(16) =186a(17) =266a(18) =221a(19) =86a(20) =14a(21) =5a(22) =41a(23) =223a(24) =881a(25) =2344a(26) =4238a(27) =4885a(28) =3451a(29) =1296
External references
- oeis: A243207