Numbers k such that phi(k + 1) divides sigma(k).

Terms

a(0) =1a(1) =3a(2) =5a(3) =6a(4) =7a(5) =11a(6) =14a(7) =15a(8) =17a(9) =23a(10) =24a(11) =28a(12) =31a(13) =33a(14) =35a(15) =47a(16) =51a(17) =53a(18) =54a(19) =55a(20) =69a(21) =71a(22) =77a(23) =87a(24) =94a(25) =107a(26) =110a(27) =127a(28) =155a(29) =170