84948077733domain: NAppears in sequencesNumber of (n+1)X6 0..3 arrays with each element of every 2X2 subblock being the sum mod 4 of two others.at n=7A183850Number of (n+1)X9 0..3 arrays with each element of every 2X2 subblock being the sum mod 4 of two others.at n=4A183853