1114368domain: NAppears in sequencesNonunitary doubly superperfect numbers: numbers k such that nusigma(nusigma(k)) = 2*k, where nusigma(k) = sigma(k) - usigma(k) is the sum of nonunitary divisors of k (A048146).at n=7A329881Number of n-digit left- or right-truncatable primes with no consecutive zero digits.at n=20A346662