Numbers k such that phi(k) | sigma(k + 13).

Terms

a(0) =1a(1) =2a(2) =4a(3) =6a(4) =7a(5) =8a(6) =9a(7) =10a(8) =11a(9) =15a(10) =20a(11) =25a(12) =27a(13) =34a(14) =38a(15) =41a(16) =42a(17) =44a(18) =56a(19) =57a(20) =64a(21) =66a(22) =80a(23) =82a(24) =120a(25) =122a(26) =128a(27) =146a(28) =152a(29) =155