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%I #12 May 20 2022 03:27:10
%S 1,2,3,7,22,32,49,52,66,70,93,94,97,98,115,119,121,127,169,170,196,
%T 214,241,242,256,265,337,343,364,441,450,513,529,567,577,578,597,679,
%U 723,784,800,841,967,1058,1225,1249,1369,1444,1521,1682,1731,1802,1849
%N Numbers k such that sigma(k) + sigma(sigma(k)) is prime.
%H Amiram Eldar, <a href="/A067738/b067738.txt">Table of n, a(n) for n = 1..10000</a>
%t Select[Range[2000],PrimeQ[DivisorSigma[1,#]+DivisorSigma[1, DivisorSigma[ 1,#]]]&] (* _Harvey P. Dale_, Apr 02 2018 *)
%Y Cf. A000203, A023194, A051027.
%K easy,nonn
%O 1,2
%A _Benoit Cloitre_, Feb 23 2002
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