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.

A079541 Numbers n such that phi(n) = d(n).

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%I A079541 #19 Feb 16 2022 11:19:32
%S A079541 1,3,8,10,18,24,30
%N A079541 Numbers n such that phi(n) = d(n).
%C A079541 Duplicate of A020488. - _Peter Luschny_, Aug 26 2011
%D A079541 D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, p. 11.
%t A079541 Select[Range[500],EulerPhi[#]==DivisorSigma[0,#]&] (* _Harvey P. Dale_, Jun 18 2011 *)
%Y A079541 Cf. A000010, A000005, A063070.
%K A079541 dead
%O A079541 1,2
%A A079541 _N. J. A. Sloane_, Jan 23 2003
%E A079541 Corrected by _Harvey P. Dale_, Jun 18 2011