Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, with every occupancy equal to zero or two.

A221405

Number of nX4 arrays of occupancy after each element stays put or moves to some horizontal or vertical neighbor, with every occupancy equal to zero or two.

Terms

    a(0) =4a(1) =44a(2) =436a(3) =4518a(4) =47156a(5) =492102a(6) =5133044a(7) =53529806a(8) =558164472a(9) =5819704716a(10) =60677191216a(11) =632619159318

External references