54473domain: NAppears in sequencesNumbers n such that sigma(phi(n))/sigma(n) = 3.at n=11A067383Frobenius number of the numerical semigroup generated by four consecutive tetrahedral numbers.at n=17A069761Numbers k such that the first 9 decimal digits of the k-th Fibonacci number is 1-9 pandigital.at n=26A112516