Number of nX3 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
A201620
Number of nX3 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
Terms
- a(0) =4a(1) =56a(2) =378a(3) =3699a(4) =31802a(5) =256836a(6) =1877283a(7) =12466658a(8) =75830797a(9) =426330762a(10) =2234037739a(11) =10991599638a(12) =51096736814a(13) =225648517165a(14) =951032245643
External references
- oeis: A201620