888997domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes with digit sum = 49.at n=21A106779Number of nX4 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,3,2,1,2 for x=0,1,2,3,4.at n=8A197238Prime numbersat n=70487