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 A250717 #21 Dec 01 2014 10:53:27
%S A250717 5,17,97,257,337,641,881,2417,2657,4177,4721,6577,10657,14657,14897,
%T A250717 28817,54721,65537,65617,66161,80177,83537,83777,130337,134417,149057,
%U A250717 260017,279857,280097,283937,394721,531457,596977,1049201,1050977,1055137,1178897
%N A250717 Primes of the form 4^x + y^4 with x, y > 0.
%C A250717 Subsequence of A250481. Also, except for the first term, subsequence of A002645.
%e A250717 257 is in this sequence because 4^4+1^4=257.
%e A250717 881 is in this sequence because 4^4+5^4=881.
%t A250717 f[x_, y_]:= 4^x + y^4; lst={}; Do[p=f[x, y]; If[PrimeQ[p], AppendTo[lst, p]], {y, 50}, {x, 50}]; Take[Union[lst], 50]
%Y A250717 Cf. A250545.
%Y A250717 Cf. similar sequences listed in A250481.
%K A250717 nonn,less
%O A250717 1,1
%A A250717 _Vincenzo Librandi_, Nov 27 2014