Number of n X 2 0..2 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order.

A223120

Number of n X 2 0..2 arrays with no more than floor(nX2/2) elements equal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..2 order.

Terms

    a(0) =1a(1) =10a(2) =72a(3) =664a(4) =5376a(5) =47968a(6) =406400a(7) =3585408a(8) =30987264a(9) =272565760a(10) =2378450944a(11) =20921604096a(12) =183506403328

External references