A015805 - OEIS

%I #17 Aug 31 2018 02:54:16

%S 24,38,42,54,60,70,92,114,154,168,182,238,266,315,322,378,406,434,504,

%T 518,574,602,630,658,742,760,826,854,858,938,950,994,1022,1080,1106,

%U 1162,1246,1350,1358,1414,1442,1498,1526,1582,1778,1820,1834

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

%H Vincenzo Librandi, <a href="/A015805/b015805.txt">Table of n, a(n) for n = 1..1000</a>

%t Select[Range[10000], Divisible[DivisorSigma[1, #], EulerPhi[#] + 12] &] (* _David Nacin_, Mar 01 2012 *)

%K nonn

%O 1,1

%A _Robert G. Wilson v_

%E Offset changed from 0 to 1 by _Vincenzo Librandi_, Mar 06 2012