230917domain: NAppears in sequencesNumber of 2 X 2 matrices with all elements in {0,1,...,n} and nonnegative determinant.at n=25A210290Numbers k such that sigma(k) = psi(k) + tau(k) + omega(k)^5.at n=22A391447Numbers k such that sigma(k) = psi(k) + tau(k)^2 + omega(k).at n=20A392518