72820domain: NAppears in sequencesSelf-convolution of row n of array T given by A026736.at n=9A027215Numbers k such that 10*R_k + 9 is prime, where R_k = 11...1 is the repunit (A002275) of length k.at n=11A056659Numbers n such that 3^n-2^(n-1) is prime.at n=39A095906Numbers k such that (20^k - 1)^2 - 2 is prime.at n=8A364080