333727333domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(1) = 2; for n>=1, a(n+1) is the smallest palindromic prime with a(n) as a central substring.at n=3A053600Beginning with 2, a(n+1) is the smallest palindromic prime obtained by placing identical digits on both sides of a(n).at n=3A090275Prime numbersat n=17975245