6771405domain: NAppears in sequencesNumbers n such that Product_{d|n} sigma(d) = Product_{d|n+1} sigma(d).at n=22A280087Numbers k such that t(k) = t(k+1) where t(k) = tau(k) + sigma(k) = A007503(k) is the number of subgroups of the dihedral group of order 2k.at n=30A322256