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 A250844 #13 May 09 2018 22:59:59
%S A250844 16433,33191,134033,6044737,40633543,50353607,268435463,268437857,
%T A250844 268452263,274200257,1977343127,2245762199,2494358231,4471684631,
%U A250844 4586471767,13841567137,21870016807,21870117649,52523350487,54500676887,78364166497,92205451297,97157445863
%N A250844 Primes of the form 7^x + y^7 with x, y > 0.
%C A250844 Conjecture: a(n+1)>=a(n)+42, with equality for infinitely many n,
%C A250844 namely those of the form a(n)=7^1+y^7, a(n+1)=7^2+y^7. - _Robert Israel_, May 09 2018
%H A250844 Robert Israel, <a href="/A250844/b250844.txt">Table of n, a(n) for n = 1..10000</a>
%e A250844 16433 is in this sequence because 16433 is prime and 7^2+3^7 = 16433.
%e A250844 33191 is in this sequence because 33191 is prime and 7^5+4^7 = 33191.
%p A250844 N:= 10^12: # to get all terms <= N
%p A250844 sort(select(isprime, [seq(seq(7^x+y^7, y=2..floor((N-7^x)^(1/7)),2),x=1..floor(log[7](N)))])); # _Robert Israel_, May 09 2018
%t A250844 f[x_, y_]:= 7^x + y^7; lst={}; Do[p=f[x, y]; If[PrimeQ[p], AppendTo[lst, p]], {y, 50}, {x, 50}]; Take[Union[lst], 30]
%t A250844 With[{nn=40},Take[Sort[Select[7^#[[1]]+#[[2]]^7&/@Tuples[Range[nn],2], PrimeQ]],nn]] (* _Harvey P. Dale_, May 28 2015 *)
%Y A250844 Cf. A250715.
%Y A250844 Cf. similar sequences listed in A250481.
%K A250844 nonn
%O A250844 1,1
%A A250844 _Vincenzo Librandi_, Dec 01 2014