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 A104068 #19 Nov 08 2023 08:08:19
%S A104068 23,83,1073741843,5846006549323611672814739330865132078623730171923,
%T A104068 74751027079122046462216955587793573067050655862760405902609490213261724339546970300512875500623813013973275600053770769378323738155015176163371603062328757260320680744718580942157810765768356266003
%N A104068 Primes of the form 2^k + 19.
%F A104068 a(n) = 2^A057221(n) + 19. - _Elmo R. Oliveira_, Nov 08 2023
%t A104068 a = Delete[Union[Flatten[Table[If [PrimeQ[2^n + 19] == True, 2^n + 19, 0], {n, 1, 400}]]], 1]
%o A104068 (Magma) [ a: n in [0..750] | IsPrime(a) where a is 2^n+19 ] // _Vincenzo Librandi_, Nov 13 2010
%Y A104068 Cf. A000040, A057221.
%K A104068 nonn
%O A104068 1,1
%A A104068 _Roger L. Bagula_, Mar 02 2005