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

Terms

a(0) =1a(1) =45a(2) =65a(3) =87a(4) =117a(5) =362a(6) =1053a(7) =1257a(8) =1282a(9) =1539a(10) =1798a(11) =2962a(12) =2966a(13) =3478a(14) =5002a(15) =5242a(16) =5932a(17) =9272a(18) =9374a(19) =9477a(20) =10550a(21) =10732a(22) =12975a(23) =13526a(24) =14427a(25) =20025a(26) =21782a(27) =21982a(28) =21986a(29) =22436