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%I #18 May 09 2024 02:54:13
%S 1,6,120,672,30240,32760,33550336,459818240,1379454720,8589869056,
%T 31998395520,51001180160,137438691328,153003540480,30823866178560,
%U 796928461056000,6088728021160320,212517062615531520,2305843008139952128,69357059049509038080,143573364313605309726720
%N Numbers k such that sigma(k)/k, sigma_3(k)/k, sigma_5(k)/k and sigma_7(k)/k are all integers.
%H Amiram Eldar, <a href="/A076234/b076234.txt">Table of n, a(n) for n = 1..55</a>
%o (PARI) isok(n) = !(sigma(n) % n) && !(sigma(n, 3) % n) && !(sigma(n, 5) % n) && !(sigma(n, 7) % n); \\ _Michel Marcus_, Dec 26 2013
%Y Cf. A000203, A001158, A001160, A013955.
%Y Cf. A007691, A046763, A055709, A076231, A076233.
%Y Cf. A066289 (k divides sigma_m(k) for all odd m).
%K nonn
%O 1,2
%A _Labos Elemer_, Oct 04 2002
%E a(13)-a(18) from _Donovan Johnson_, May 08 2010
%E a(19)-a(21) from _Amiram Eldar_, May 09 2024
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