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 A215699 #5 Aug 22 2012 21:07:39 %S A215699 0,1,1,28,160,1247 %N A215699 Number of primes of the form 1 + b^512 for 1 < b < 10^n. %C A215699 Primes 1 + b^512 are a form of generalized Fermat primes. %C A215699 It is conjectured that a(n) is asymptotic to 0.0146271*li(10^n) %H A215699 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 A215699 Yves Gallot, <a href="http://yves.gallot.pagesperso-orange.fr/primes/stat.html">How many prime numbers appear in a sequence ?</a> %H A215699 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> %e A215699 a(3) = 1 because the generalized Fermat numbers F_9(b) where b<10^3 are prime only for b = 46. %o A215699 (PARI) a(n) = sum(b=1, 10^n/2-1, isprime((2*b)^512+1)) %Y A215699 Cf. A215047, A215048, A215049, A215050, A215051, A215057, A215058, A215698. %K A215699 nonn %O A215699 1,4 %A A215699 _Henryk Dabrowski_, Aug 21 2012