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Numbers k such that phi(k + 12) | sigma(k).
1

%I #16 Aug 31 2018 02:53:43

%S 6,14,23,24,30,33,38,51,54,60,66,78,84,87,96,102,109,120,132,141,159,

%T 168,174,204,210,246,248,249,267,276,280,321,330,345,354,372,378,380,

%U 406,411,426,495,506,519,537,564,591,606,636,642,690,699,789,822,852

%N Numbers k such that phi(k + 12) | sigma(k).

%H Vincenzo Librandi, <a href="/A015832/b015832.txt">Table of n, a(n) for n = 1..2000</a>

%t Select[Range[3000], Divisible[DivisorSigma[1, #], EulerPhi[12 + #]] &] (* _David Nacin_, Mar 03 2012 *)

%K nonn

%O 1,1

%A _Robert G. Wilson v_