Multiply-perfect numbers: n divides sigma(n).

Terms

a(0) =1a(1) =6a(2) =28a(3) =120a(4) =496a(5) =672a(6) =8128a(7) =30240a(8) =32760a(9) =523776a(10) =2178540a(11) =23569920a(12) =33550336a(13) =45532800a(14) =142990848a(15) =459818240a(16) =1379454720a(17) =1476304896a(18) =8589869056a(19) =14182439040a(20) =31998395520a(21) =43861478400a(22) =51001180160a(23) =66433720320a(24) =137438691328a(25) =153003540480a(26) =403031236608