134619domain: NAppears in sequencesNumber of 0..n arrays x(0..3) of 4 elements without any two consecutive increases or two consecutive decreases.at n=21A200839Number of (n+2)X(6+2) 0..1 arrays with every 3X3 subblock diagonal sum plus antidiagonal sum nondecreasing horizontally, vertically and ne-to-sw antidiagonally.at n=13A253839