661458domain: NAppears in sequencesNumber of primes less than 10^n using the x-th root approximation formula 1/(x^(1/x) - 1/x - 1) where x = 10^n.at n=6A103649Number of isomeric aza-benzenoids with one nitrogen atom and n hexagons.at n=9A121949Floor((10^n)/(log(10^n) - 1)).at n=6A193257