313650domain: NAppears in sequencesNumber of orthogonal rectangles with vertices on an n X n square grid of points but with no vertices on the grid's diagonals.at n=36A285956a(n) = Trinomial(2*n+1, 4) = (1/6)*n*(2*n + 1)*(2*n^2 + 9*n + 1), n >= 0.at n=25A302709