Number of 3Xn 0..3 arrays with exactly floor(3Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.
A222750
Number of 3Xn 0..3 arrays with exactly floor(3Xn/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.
Terms
- a(0) =0a(1) =20a(2) =2438a(3) =126947a(4) =6363724a(5) =390671426a(6) =20825891902
External references
- oeis: A222750