48265519domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of n X n 0,1 arrays indicating 2X2 subblocks of some larger (n+1)X(n+1) binary array having a sum of three or less, with rows and columns of the latter in lexicographically nondecreasing order.at n=6A227264Prime numbersat n=2903058