Number of 2Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.
A221508
Number of 2Xn arrays of occupancy after each element moves to some horizontal, diagonal or antidiagonal neighbor, without consecutive moves in the same direction.
Terms
- a(0) =0a(1) =9a(2) =44a(3) =446a(4) =3334a(5) =27540a(6) =219070a(7) =1766136a(8) =14168766a(9) =113870162a(10) =914550470a(11) =7346946970a(12) =59015933032a(13) =474072774244
External references
- oeis: A221508