111181domain: NAppears in sequencesNumber of different strings of length n+6 obtained from "123...n" by iteratively duplicating any substring.at n=13A137739a(n) = Sum_{d|n} phi(d^tau(d)).at n=20A179115Least k > a(n-1) such that k^3 has no digit in common with a(n-1) and a(n+1), a(0)=0.at n=32A294662