238313domain: NPropertiesPrimalityPrimeyesAppears in sequencesNumbers k such that the continued fraction for sqrt(k) has odd period and if the last term of the periodic part is deleted the two central terms are both 75.at n=5A031663Primes of the form 16*m^2 + 169, m=1,2,3,...at n=31A087862Prime numbersat n=21086