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

Terms

a(0) =1a(1) =5a(2) =221a(3) =763a(4) =2759a(5) =11303a(6) =12749a(7) =13079a(8) =20677a(9) =33725a(10) =42253a(11) =75101a(12) =96193a(13) =140225a(14) =160369a(15) =168113a(16) =171667a(17) =195889a(18) =227099a(19) =229969a(20) =269161a(21) =275971a(22) =316129a(23) =344317a(24) =385033a(25) =387163a(26) =392677a(27) =437999a(28) =498253a(29) =528209