6854400domain: NAppears in sequencesIrrational unitary phi amicable number: numbers b such that uphi(a) = uphi(b) = 2*(a^2-b^2)^(1/2) where uphi = A047994.at n=4A046709Determinant of the n X n matrix formed by placing 1..n^2 in L-shaped gnomons in alternating directions.at n=6A363376