188457984domain: NAppears in sequencesa(n) = 2^(n-1)*binomial(2*n-1,n-1)^2.at n=7A116421Number of 7Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 0 1 vertically.at n=13A208146