Numbers k such that sigma(k+1) = 2*phi(k).

Terms

a(0) =13a(1) =43a(2) =109a(3) =151a(4) =589a(5) =883a(6) =2143a(7) =2725a(8) =4825a(9) =4921a(10) =9541a(11) =13189a(12) =21637a(13) =22249a(14) =22489a(15) =29971a(16) =30229a(17) =33787a(18) =36247a(19) =72541a(20) =73513a(21) =83287a(22) =94489a(23) =109213a(24) =113269a(25) =117367a(26) =189103a(27) =190489a(28) =198457a(29) =216529