197074944domain: NAppears in sequencesa(n) = Product_{i=2..n} A001222(i) * Sum_{i=2..n} 1/A001222(i).at n=26A067580Number of (n+1) X 4 0..2 arrays with every 2 X 3 or 3 X 2 subblock having exactly two counterclockwise and two clockwise edge increases.at n=13A206089