Numbers n such that 13^phi(n) == 1 (mod n^2), where phi(n) = A000010(n).

Terms

a(0) =2a(1) =863a(2) =1726a(3) =3452a(4) =371953a(5) =743906a(6) =1487812a(7) =1747591a(8) =1859765a(9) =2975624a(10) =3495182a(11) =3719530a(12) =5242773a(13) =6990364a(14) =7439060a(15) =8737955a(16) =10485546a(17) =14878120a(18) =15993979a(19) =17475910a(20) =20971092a(21) =26213865a(22) =29756240a(23) =31987958a(24) =34951820a(25) =41942184a(26) =47981937a(27) =52427730a(28) =59512480