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 A177027 #11 Jan 18 2024 18:28:58
%S A177027 13,19489357,2357967373,23225154419887808146560828362864653
%N A177027 Primes of the form 11^n+3^n-1.
%C A177027 The next term (a(5)) has 133 digits. - _Harvey P. Dale_, Jan 18 2024
%F A177027 a(n) = 11^A177030(n)+3^A177030(n)-1.
%t A177027 Select[Table[11^n+3^n-1,{n,40}],PrimeQ] (* _Harvey P. Dale_, Jan 18 2024 *)
%o A177027 (Magma) [ a: n in [0..350] | IsPrime(a) where a is 11^n+3^n-1^n]
%Y A177027 Cf. A155623, A177030
%K A177027 nonn,less
%O A177027 1,1
%A A177027 _Vincenzo Librandi_, Dec 09 2010