Triangle T(n, k) = Numbers of 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.
A243211
Triangle T(n, k) = Numbers of 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) =3a(4) =3a(5) =1a(6) =6a(7) =15a(8) =15a(9) =3a(10) =1a(11) =10a(12) =45a(13) =107a(14) =128a(15) =63a(16) =10a(17) =1a(18) =15a(19) =105a(20) =428a(21) =1062a(22) =1566a(23) =1276a(24) =507a(25) =69a(26) =1a(27) =21a(28) =210a(29) =1282
External references
- oeis: A243211