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Numbers n such that phi(n) divides n+2.
1

%I #19 Oct 27 2023 08:20:25

%S 1,2,4,6,10,30,70,510,2590,131070,3359230,167247870,8589934590,

%T 13985925344264190

%N Numbers n such that phi(n) divides n+2.

%C Contains 2 * A203966 as a subsequence. - _Max Alekseyev_, Oct 27 2023

%t Select[Range[50000000],Divisible[#+2,EulerPhi[#]]&]

%Y Cf. A000010, A050474, A207574, A202855, A203966.

%K nonn,more,hard

%O 1,2

%A _José María Grau Ribas_, Feb 19 2012

%E a(12)-a(13) from _Donovan Johnson_, Mar 01 2012

%E a(14) from _Max Alekseyev_, Oct 27 2023