118216domain: NAppears in sequencesNumbers n such that 5*10^n + 8*R_n + 1 is prime, where R_n = 11...1 is the repunit (A002275) of length n.at n=12A103024Numbers k such that 4^k + 25 is prime.at n=37A204388G.f. A(x) satisfies A(x) = 1/sqrt( (1 - 2*x*A(x)^3) * (1 - 2*x*A(x)) ).at n=6A379331