3912492domain: NAppears in sequencesNumber of perfect matchings in the C_{2n} X P_3 graph (C_{2n} is the cycle graph on 2n vertices and P_3 is the path graph on 3 vertices).at n=10A102091Numbers w + x + y + z where (w,x,y,z) are nonnegative solutions to the Diophantine equation w^2 + x^2 + y^2 + z^2 = w*x*y*z.at n=25A385713