307396domain: NAppears in sequencesNumbers k such that k | (3^k + 3).at n=25A015888Numbers n such that n | 11^n + 11.at n=27A015903Numbers k for which phi(k^2) = phi(k-1) * phi(k+1).at n=11A220169Solutions to A000010(x) + A000010(x-1) = A000010(2*x).at n=25A299535