63718domain: NAppears in sequencesNumbers k such that 10^k + 2*R_k + 1 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=12A102929Sequence A154647 adjusted to leading ones:t(n,m)=A154647(n,m)-A154647(n,0)+1.at n=22A174678Sequence A154647 adjusted to leading ones:t(n,m)=A154647(n,m)-A154647(n,0)+1.at n=26A174678