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 A273809 #7 Sep 08 2022 08:46:17
%S A273809 491,503,743,4294967783,
%T A273809 115792089237316195423570985008687907853269984665640564039457584007913129640423
%N A273809 Primes of the form 2^(2^n) + 487.
%C A273809 Terms given correspond to n = 1, 2, 3, 5 and 8.
%C A273809 Next term >= 2^2^35 + 487. - _Charles R Greathouse IV_, Jun 07 2016
%t A273809 Select[Table[2^(2^n) + 487, {n, 0, 15}], PrimeQ]
%o A273809 (Magma) [a: n in [0..16] | IsPrime(a) where a is 2^(2^n)+487];
%o A273809 (PARI) for(n=0,8, if(ispseudoprime(t=2^2^n+357), print1(t", "))) \\ _Charles R Greathouse IV_, Jun 07 2016
%Y A273809 Cf. similar sequences listed in A273547.
%K A273809 nonn
%O A273809 1,1
%A A273809 _Vincenzo Librandi_, Jun 03 2016