456666domain: NAppears in sequences4th elementary symmetric function of {1, p(1), p(2), ..., p(n-1)}, where p(0) = 1.at n=5A024524Number of 5Xn 0..1 arrays avoiding 0 0 1 and 0 1 1 horizontally and 0 0 1 and 1 1 0 vertically.at n=10A207405Composite numbers k such that k*phi(k) is in A002378.at n=36A256545