511428domain: NAppears in sequencesMaximal entry in row n of triangle in A169950.at n=21A169954Number x such that sigma(x) = usigma(x) + (-1)sigma(x), where sigma(x) is the sum of divisors of x (A000203), usigma(x) is the sum of unitary divisors of x (A034448) and (-1)sigma(x) is defined in A049060.at n=12A258106