271092domain: NAppears in sequencesNumerator of Euler(n, 12/31).at n=4A157693Number 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=11A258106