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%I #31 Feb 23 2024 07:25:40
%S 1,6,15,28,84,95,140,182,190,248,270,287,308,357,420,455,477,496,570,
%T 672,744,819,840,910,1199,1428,1488,1547,1638,1722,1848,1892,2295,
%U 2398,2480,2660,2730,3339,3417,3472,3515,3596,3640,3720,3780,3956,4064,4095
%N Numbers k such that sigma(k) divides k*phi(k).
%H Harry J. Smith, <a href="/A066995/b066995.txt">Table of n, a(n) for n = 1..1000</a>
%t Select[Range[4500],Divisible[# EulerPhi[#],DivisorSigma[1,#]]&] (* _Harvey P. Dale_, Mar 19 2011 *)
%o (PARI) { n=0; for (m=1, 10^10, if ((m*eulerphi(m)) % sigma(m) == 0 , write("b066995.txt", n++, " ", m); if (n==1000, return)) ) } \\ _Harry J. Smith_, Apr 24 2010
%o (PARI) isok(n) = frac(n*eulerphi(n)/sigma(n)) == 0; \\ _Michel Marcus_, Jan 31 2018
%o (GAP) Filtered([1..10^5], n -> n*Phi(n) mod Sigma(n) = 0); # _Muniru A Asiru_, Jan 31 2018
%Y Cf. A001599, A011775.
%K nonn
%O 1,2
%A _Benoit Cloitre_, Jan 27 2002
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