1098439domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumber of n X 2 0,1 arrays indicating 2 X 2 subblocks of some larger (n+1) X 3 binary array having a sum of two, with rows and columns of the latter in lexicographically nondecreasing order.at n=21A227099Prime numbersat n=85605