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 A156940 #15 Sep 04 2024 19:05:33
%S A156940 13,19,43,139,523,32779,8388619,536870923,2147483659,
%T A156940 36028797018963979,2361183241434822606859,151115727451828646838283,
%U A156940 254629497041810760783555711051172270131433549208242031329517556169297662470417088272924683
%N A156940 Primes of the form 2^k + 11.
%F A156940 a(n) = 2^A102633(n) + 11. - _R. J. Mathar_, Feb 20 2009
%t A156940 Delete[Union[Table[If[PrimeQ[2^n + 11], 2^n + 11, 0], {n, 1, 200}]],1]
%o A156940 (Magma) [ a: n in [0..350] | IsPrime(a) where a is 2^n+11 ]; // _Vincenzo Librandi_, Nov 26 2010
%Y A156940 Cf. A057733, A123250, A104066.
%K A156940 nonn
%O A156940 1,1
%A A156940 Edwin Dyke (ed.dyke(AT)btinternet.com), Feb 18 2009
%E A156940 a(13) from _Vincenzo Librandi_, Apr 29 2010