This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A118721 #3 May 10 2018 09:44:03
%S A118721 2,3,5,7,11,23,29,41,47,67,83,89,101,113,131,137,139,157,179,191,197,
%T A118721 199,227,263,269,281,311,317,337,353,359,379,401,409,443,449,461,467,
%U A118721 487,557,571,577,599,641,647,683,719,751,797,809,821,827,829,863,881
%N A118721 Chen primes for which the sum of the digits is also a Chen prime.
%H A118721 Harvey P. Dale, <a href="/A118721/b118721.txt">Table of n, a(n) for n = 1..1000</a>
%e A118721 29 is in the sequence because (1) it is a Chen prime and (2) the sum of its digits 2+9=11 is also a Chen prime.
%t A118721 With[{ch=Select[Prime[Range[200]],PrimeOmega[#+2]<3&]},Select[ch, MemberQ[ ch, Total[IntegerDigits[#]]]&]] (* _Harvey P. Dale_, May 10 2018 *)
%Y A118721 Cf. A109611.
%K A118721 base,nonn
%O A118721 1,1
%A A118721 Luc Stevens (lms022(AT)yahoo.com), May 21 2006