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 A249666 #20 Aug 04 2019 13:02:38
%S A249666 3,4,6,10,12,16,22,24,30,36,42,46,50,54,56,66,70,76,78,84,90,92,100,
%T A249666 114,116,120,126,130,132,142,144,156,160,170,174,176,180,186,192,196,
%U A249666 202,210,220,222,226,232,234,240,246,250,252,276,280,282,286,288,294,300,306,310,324
%N A249666 Numbers n such that the sum of n and the largest prime<n (A151799(n)) is prime.
%H A249666 Harvey P. Dale, <a href="/A249666/b249666.txt">Table of n, a(n) for n = 1..1000</a>
%e A249666 66 is in the sequence because A151799(66)=61, and 66+61=127 is prime.
%t A249666 Select[Range[400],PrimeQ[#+NextPrime[#,-1]]&] (* _Harvey P. Dale_, Aug 04 2019 *)
%o A249666 (PARI) {for(i=3,10^3,k=i+precprime(i-1);if(isprime(k),print1(i,", ")))}
%Y A249666 Cf. A151799, A249624, A249667, A249676.
%K A249666 nonn
%O A249666 1,1
%A A249666 _Antonio Roldán_, Dec 03 2014