25721308800domain: NAppears in sequencesOrder of universal Chevalley group B_2(q), q = prime power.at n=7A003931a(n) = (1/2) * (number of n X n 0..10 matrices with MM' mod 11 = I).at n=4A071309Order of the symplectic group of 4 X 4 matrices over Z_n.at n=10A364771