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

Terms

a(0) =2a(1) =38a(2) =62a(3) =346a(4) =1298a(5) =7898a(6) =22682a(7) =24382a(8) =93022a(9) =108194a(10) =143362a(11) =171982a(12) =192718a(13) =264766a(14) =587638a(15) =986642a(16) =1236898a(17) =1441042a(18) =1604422a(19) =2228582a(20) =4146434a(21) =5070314a(22) =5631718a(23) =6687046a(24) =10223918a(25) =10695182a(26) =12465158a(27) =14221738a(28) =15148522a(29) =21718622