10310983domain: NPropertiesPrimalityPrimeyesAppears in sequencesa(n) = ((5+sqrt(2))*(1+sqrt(2))^n + (5-sqrt(2))*(1-sqrt(2))^n)/2.at n=17A162268Numbers k such that k^2 + 23 is twice a square.at n=17A387549Prime numbersat n=683849