90728

Appears in sequences

• Number of nX7 0..1 arrays with every element equal to 0, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=5A303241
• Number of 6Xn 0..1 arrays with every element equal to 0, 2, 3, 5 or 6 horizontally, diagonally or antidiagonally adjacent elements, with upper left element zero.at n=6A303246
• G.f. A(x) = lim_{n->infinity} (1 - P(n,x))/(-2*x)^n, where P(1,x) = 1/sqrt(1 - 4*x), and P(n+1,x) = 1/sqrt(1 - 4*x + 4*x*P(n,x)) for n >= 1.at n=10A351510