Numbers k such that sigma(k) = sigma(k+4).

Terms

a(0) =51a(1) =66a(2) =115a(3) =220a(4) =319a(5) =1003a(6) =2585a(7) =4024a(8) =4183a(9) =4195a(10) =5720a(11) =5826a(12) =5959a(13) =8004a(14) =8374a(15) =11659a(16) =12367a(17) =12561a(18) =13581a(19) =14338a(20) =15365a(21) =16116a(22) =17840a(23) =18718a(24) =20541a(25) =25130a(26) =29393a(27) =30170a(28) =32665a(29) =36516