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Primes arising in A048969.
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%I #12 Jul 16 2021 05:23:03

%S 3,7,13,19,31,61,127,127,331,307,307,631,1801,1723,3169,1093,1723,

%T 3571,1093,3221,5419,3541,3541,8269,5113,5113,13267,8011,8011,16651,

%U 10303,19441,10303,24571,17293,17293,28057,30103,55897,28057,59221,30103,8191,19531

%N Primes arising in A048969.

%t p[n_]:=Module[{c=DivisorSigma[1,n]/DivisorSigma[0,n]},If[PrimeQ[c],c,0]]; nn=62000;With[{comps=Complement[Range[nn],Prime[Range[PrimePi[nn]]]]}, Select[ p/@comps,#!=0&]] (* _Harvey P. Dale_, Feb 19 2012 *)

%Y Cf. A048968, A048969.

%K nonn

%O 1,1

%A _G. L. Honaker, Jr._

%E More terms from Antonio G. Astudillo (afg_astudillo(AT)hotmail.com), Jun 17 2001

%E More terms from _Sean A. Irvine_, Jul 16 2021