481176domain: NAppears in sequencesLargest k such that k! < 2^(2^n).at n=23A152909Number of (n+1) X (7+1) 0..1 arrays with every 2 X 2 subblock ne-sw antidiagonal difference nondecreasing horizontally and nw+se diagonal sum nondecreasing vertically.at n=20A258553