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 A088553 #14 Jul 05 2024 07:30:57
%S A088553 2,5,13,41,1093,797161,21523361,926510094425921,
%T A088553 1716841910146256242328924544641,3754733257489862401973357979128773,
%U A088553 6957596529882152968992225251835887181478451547013
%N A088553 Primes of the form (3^k-1)/2 or (3^k+1)/2.
%C A088553 The next term is too large to include.
%C A088553 The next term has 258 digits. - _Harvey P. Dale_, Dec 04 2018
%H A088553 Amiram Eldar, <a href="/A088553/b088553.txt">Table of n, a(n) for n = 1..15</a>
%t A088553 Select[Flatten[Table[(3^x+{1,-1})/2,{x,150}]],PrimeQ] (* _Harvey P. Dale_, Dec 04 2018 *)
%Y A088553 Cf. A028491, A096723, A171381.
%K A088553 nonn
%O A088553 1,1
%A A088553 _Cino Hilliard_, Nov 17 2003
%E A088553 Edited by _Don Reble_, May 03 2006