1/3 the number of nX3 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

A185553

1/3 the number of nX3 0..2 arrays with every element equal to exactly one or two of its horizontal and vertical neighbors.

Terms

    a(0) =1a(1) =26a(2) =224a(3) =2530a(4) =25496a(5) =269496a(6) =2792166a(7) =29168100a(8) =303674928a(9) =3165976954a(10) =32988466864a(11) =343808442136

External references