405565189domain: NPropertiesPrimalityPrimeyesAppears in sequencesPrimes of the form 8k+5 generated recursively: a(1)=5, a(n) = least prime p == 5 (mod 8) with p | 4+Q^2, where Q is the product of all previous terms in the sequence.at n=5A057208Prime numbersat n=21617161