Numbers m having at least one divisor d such that m divides sigma(d).

Terms

a(0) =1a(1) =6a(2) =12a(3) =28a(4) =56a(5) =120a(6) =360a(7) =496a(8) =672a(9) =992a(10) =2016a(11) =8128a(12) =16256a(13) =30240a(14) =32760a(15) =60480a(16) =65520a(17) =120960a(18) =131040a(19) =523776a(20) =1571328a(21) =2178540a(22) =4357080a(23) =8714160a(24) =23569920a(25) =33550336a(26) =45532800a(27) =47139840a(28) =67100672a(29) =91065600