89178domain: NAppears in sequencesNumbers n whose sum of divisors equals the sum of divisors of 2n+1.at n=23A272553Numbers n such that usigma(n) = usigma(2*n+1) where usigma(n) = A034448(n).at n=10A286837a(n) = A000041(n) * A000009(n).at n=22A304991