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 A112245 #8 Jun 13 2017 10:15:08 %S A112245 287,1695,81359,512895 %N A112245 Numbers k such that 65537*2^k+1 is prime. %C A112245 Note that 65537=2^16+1 is the largest known Fermat prime. These n yield provable primes. The primes are the smallest numbers in classes 303, 1711 and 81375 of the phi iteration (see A007755). %C A112245 Jacques Molne found 512895. The corresponding provable prime is the smallest number in class 512911 of the Phi iteration. %o A112245 (PARI) is(n)=ispseudoprime(65537*2^n+1) \\ _Charles R Greathouse IV_, Jun 13 2017 %Y A112245 Cf. A002253, A002254, A002259, A053345 (F*2^n+1 is prime, where F is a Fermat prime). %K A112245 nonn,hard %O A112245 1,1 %A A112245 _T. D. Noe_, Aug 30 2005, Aug 26 2007