OU-Sigma multiperfect numbers.

Terms

a(0) =1a(1) =6a(2) =28a(3) =90a(4) =120a(5) =496a(6) =672a(7) =8128a(8) =10080a(9) =63700a(10) =220500a(11) =523776a(12) =1323000a(13) =1528800a(14) =2056320a(15) =7856640a(16) =33550336a(17) =44553600a(18) =162729000a(19) =252927360a(20) =459818240a(21) =1379454720a(22) =1476304896a(23) =1980840960a(24) =8589869056