16666666domain: NAppears in sequencesa(n) = floor(10^8/n).at n=5A033424Numbers n such that (n+n+1) divides the decimal concatenation [n, n+1].at n=14A173712Number of composites removed in each step in the Sieve of Eratosthenes for 10^8.at n=1A227797a(n) = (5*10^n - 2)/3.at n=7A246057