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 A277434 #25 Nov 10 2016 15:24:39
%S A277434 2,7,97,708158977
%N A277434 Primes in A001075.
%C A277434 For n >= 2, a(n) == 7 mod 30.
%C A277434 Terms in this sequence have the form A001075(2^k) [see my third comment on A001075]: a(1) = A001075(2^0) = A001075(1), a(2) = A001075(2^1) = A001075(2), a(3) = A001075(2^2) = A001075(4), and a(4) = A001075(2^4) = A001075(16). Are there more terms and, if so, will a(5) = A001075(2^16) = A001075(65536)?
%C A277434 The following terms are not prime and, thus, not in the sequence: A001075(m), for m = 8, 32, 64, 128, 256, 512, 1024. So, a(5) > 2.3619*10^585.
%C A277434 a(5), if it exists, is at least A001075(2^23) and hence has more than four million decimal digits. - _Charles R Greathouse IV_, Nov 10 2016
%H A277434 D. Alpern, <a href="https://www.alpertron.com.ar/ECM.HTM">Factorization using the Elliptic Curve Method</a>.
%t A277434 Select[LinearRecurrence[{4, -1}, {1, 2}, 30], PrimeQ] (* _Michael De Vlieger_, Oct 21 2016, after _Harvey P. Dale_ at A001075 *)
%o A277434 (PARI) lista(nn) = for (n=0, nn, if (isprime(p=polchebyshev(n,1,2)), print1(p, ", "))); \\ _Michel Marcus_, Oct 21 2016
%o A277434 (PFGW) ABC2 Linear(1, 2, 7, 26, 2^$a)
%o A277434 a: from 1 to 25
%o A277434 _Charles R Greathouse IV_, Nov 07 2016
%Y A277434 Cf. A001075.
%K A277434 nonn,hard
%O A277434 1,1
%A A277434 _Timothy L. Tiffin_, Oct 14 2016