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

Terms

a(0) =2a(1) =459a(2) =17835a(3) =34089a(4) =55419a(5) =61183a(6) =180785a(7) =194139a(8) =248501a(9) =385671a(10) =907323a(11) =988455a(12) =1374735a(13) =1407413a(14) =1408253a(15) =1452135a(16) =1749087a(17) =2451727a(18) =3026705a(19) =3263585a(20) =3831487a(21) =6541695a(22) =7633989a(23) =9336785a(24) =12750833a(25) =16543433a(26) =16573963a(27) =21248201