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 A153133 #19 Jul 14 2025 17:48:57
%S A153133 3,7,17,43,113,307,857,20707,181243,539633,14414443,129402307,
%T A153133 31389448217,1853028778786433,5559077746424707,50031613818476443,
%U A153133 150094772735952593,8862938260389989451257,26588814640432479998443
%N A153133 Primes of the form 2^k+3^(k-1).
%H A153133 Vincenzo Librandi, <a href="/A153133/b153133.txt">Table of n, a(n) for n = 1..37</a>
%t A153133 lst={};Do[p=2^n+3^(n-1);If[PrimeQ[p],AppendTo[lst,p]],{n,0,5!}];lst (* _Vladimir Joseph Stephan Orlovsky_, Jun 15 2009 *)
%t A153133 Select[3^#[[1]]+2^#[[2]]&/@Partition[Range[0,50],2,1],PrimeQ] (* _Harvey P. Dale_, Feb 19 2015 *)
%o A153133 (Magma) [a: n in [0..100] | IsPrime(a) where a is 2^n+3^(n-1)];
%Y A153133 Cf. A082400.
%K A153133 nonn
%O A153133 1,1
%A A153133 _Vincenzo Librandi_, Mar 11 2009
%E A153133 More terms from _Vladimir Joseph Stephan Orlovsky_, Jun 15 2009