340480

Appears in sequences

• Number of nX4 binary arrays with top left value 1 and no two ones adjacent horizontally, diagonally or antidiagonally.at n=7A228656
• Column 4 of A060244.at n=38A291589
• G.f. satisfies A(x) = 1 + 2*x + 2*x^2*A(x)^2.at n=13A367071