567767102431domain: NAppears in sequencesa(n) = sigma_5(n^5)/sigma(n^5).at n=3A077456a(n) is the maximal overpseudoprime q to base 2 such that the multiplicative order of 2 mod q equals A143584(n).at n=19A131952Numbers of the form (2^(p*q)-1) /((2^p-1)*(2^q-1)), where p>q are primes.at n=18A140803