Numbers k that have a record number of common divisors with sigma(k).

Terms

a(0) =1a(1) =6a(2) =24a(3) =120a(4) =672a(5) =4320a(6) =26208a(7) =30240a(8) =524160a(9) =2178540a(10) =8714160a(11) =8910720a(12) =17428320a(13) =45532800a(14) =132723360a(15) =208565280a(16) =240589440a(17) =470564640a(18) =668304000a(19) =1307124000a(20) =5228496000a(21) =10805558400a(22) =14182439040a(23) =31998395520a(24) =159991977600