27486820443domain: NAppears in sequencesNumbers k such that k^2 divides 10^k-1.at n=9A127100Numbers k not divisible by 9 such that k divides 10^k - 1 (A014950).at n=12A232769a(n) is the n-th number m such that m^2 divides n^m - 1 (or 0 if m does not exist).at n=9A333502