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

Terms

a(0) =1a(1) =2a(2) =6a(3) =14a(4) =30a(5) =40a(6) =70a(7) =140a(8) =170a(9) =174a(10) =206a(11) =215a(12) =238a(13) =390a(14) =459a(15) =518a(16) =923a(17) =957a(18) =1334a(19) =1364a(20) =1540a(21) =1634a(22) =2685a(23) =2974a(24) =4364a(25) =5180a(26) =5934a(27) =6048a(28) =6467a(29) =6510