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 A215048 #30 Aug 09 2012 13:25:46
%S A215048 3,17,110,789,6395,52610,445868,3857543,34057327
%N A215048 Number of primes of the form 1 + b^4 for 1 < b < 10^n.
%C A215048 Primes 1 + b^4 are a form of generalized Fermat primes. It is conjectured that a(n) is asymptotic to 0.66974*li(10^n).
%D A215048 Daniel Shanks, On Numbers of the Form n^4 + 1, Math. Comput. 15 (1961), 186-189.
%H A215048 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/results.html">Status of the smallest base values yielding Generalized Fermat primes</a>
%H A215048 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/stat.html">How many prime numbers appear in a sequence ?</a>
%H A215048 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/papers/ccdgfpn.html">A Problem on the Conjecture Concerning the Distribution of Generalized Fermat Prime numbers (a new method for the search for large primes)</a>
%H A215048 Mersenne Wiki, <a href="http://mersennewiki.org/index.php/User:Merfighters/listtest">Table of known GF primes b^n+1 where n (exponent) is at least 8192</a>.
%F A215048 a(n) = A214452(4*n) - 1.
%e A215048 a(1) = 3 because the only generalized Fermat primes F_2(b) where b<10^1 are the primes: 17, 257, 1297.
%t A215048 Table[Length[Select[Range[2,10^n-1]^4 + 1, PrimeQ]], {n, 5}] (* _T. D. Noe_, Aug 02 2012 *)
%o A215048 (PARI) a(n) = sum(b=1, 10^n/2-1, isprime((2*b)^4+1))
%Y A215048 Cf. A214452.
%K A215048 nonn
%O A215048 1,1
%A A215048 _Henryk Dabrowski_, Aug 01 2012