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%I #12 Aug 27 2014 01:14:17
%S 3,12,234,1080,6048,6552,435708,4713984,18506880,36197280,275890944,
%T 299980800,4138364160,13286744064,17827568640,30600708096,
%U 459010621440,2198278051200,2567400675840,3321402084000,4959751305600,295185198672000,1217745604232064
%N Numbers n for which sigma(n)/n = k+1/3 with integer k.
%e a(1)=3 since sigma(3)/3=(1+3)/3=1+1/3.
%e a(2)=12 since sigma(12)/12=(1+2+3+4+6+12)/12=28/12=7/3=2+1/3.
%o (PARI) is(n)=denominator(sigma(n,-1)-1/3)==1 \\ _Charles R Greathouse IV_, Mar 09 2014
%Y Cf. A160321 (sigma(n)/n=k+2/3), A159907 (sigma(n)/n=k+1/2).
%K nonn
%O 1,1
%A J.C. Klein (hklein(AT)planet.nl), May 08 2009
%E a(11)-a(16) from _Donovan Johnson_, May 26 2009
%E a(17)-a(23) from _Michel Marcus_, Sep 21 2012
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