Number of nX4 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
A201621
Number of nX4 0..3 arrays with rows and columns lexicographically nondecreasing and every element equal to at least one horizontal or vertical neighbor.
Terms
- a(0) =10a(1) =211a(2) =3699a(3) =91223a(4) =2111763a(5) =45733593a(6) =891142897a(7) =15644678596a(8) =249289360661
External references
- oeis: A201621