Numbers n such that phi(n + 1) | sigma(n) for n congruent to 1 (mod 3).

Terms

a(0) =1a(1) =7a(2) =28a(3) =31a(4) =55a(5) =94a(6) =127a(7) =265a(8) =322a(9) =385a(10) =406a(11) =649a(12) =1504a(13) =1624a(14) =1990a(15) =2488a(16) =3115a(17) =3154a(18) =4402a(19) =5269a(20) =6265a(21) =6460a(22) =7258a(23) =7384a(24) =7579a(25) =8191a(26) =8455a(27) =8995a(28) =9229a(29) =9799