Numbers k such that sigma(phi(sigma(k))) = phi(sigma(phi(k))).

Terms

a(0) =1a(1) =13a(2) =65a(3) =157a(4) =173a(5) =193a(6) =1093a(7) =1201a(8) =1843a(9) =2231a(10) =2753a(11) =3665a(12) =12707a(13) =13829a(14) =15269a(15) =19549a(16) =19813a(17) =20003a(18) =31601a(19) =32069a(20) =32201a(21) =34001a(22) =58091a(23) =72971a(24) =77681a(25) =80745a(26) =91505a(27) =112241a(28) =129899a(29) =153409