cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A207667 Numbers n such that phi(n) divides n+2.

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%I A207667 #19 Oct 27 2023 08:20:25
%S A207667 1,2,4,6,10,30,70,510,2590,131070,3359230,167247870,8589934590,
%T A207667 13985925344264190
%N A207667 Numbers n such that phi(n) divides n+2.
%C A207667 Contains 2 * A203966 as a subsequence. - _Max Alekseyev_, Oct 27 2023
%t A207667 Select[Range[50000000],Divisible[#+2,EulerPhi[#]]&]
%Y A207667 Cf. A000010, A050474, A207574, A202855, A203966.
%K A207667 nonn,more,hard
%O A207667 1,2
%A A207667 _José María Grau Ribas_, Feb 19 2012
%E A207667 a(12)-a(13) from _Donovan Johnson_, Mar 01 2012
%E A207667 a(14) from _Max Alekseyev_, Oct 27 2023