50641domain: NAppears in sequencesNumbers whose set of base 15 digits is {0,1}.at n=19A033051Largest k such that prime(n) divides the numerator of the k-th harmonic number (=A001008(k)).at n=10A177734Quartan semiprimes: semiprimes of the form x^4 + y^4, x>0, y>0.at n=29A182277