Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to two or fewer horizontal or vertical neighbors.

A199095

Number of nX2 0..2 arrays with values 0..2 introduced in row major order, the number of instances of each value within one of each other, and every element equal to two or fewer horizontal or vertical neighbors.

Terms

    a(0) =1a(1) =6a(2) =15a(3) =280a(4) =2040a(5) =5503a(6) =113010a(7) =857532a(8) =2340127a(9) =50784920a(10) =395160694a(11) =1085939598a(12) =24341903776a(13) =192371505064a(14) =530944513322

External references