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 A050545 #19 Jan 17 2019 10:08:17 %S A050545 3,24,105,153,188,605,795,813,839,2135,2619,4053,8333,15519,16025, %T A050545 16505,30684,40700,43683,52233,142205,222345,225333,292839,322613, %U A050545 747219,781220 %N A050545 Numbers n such that 39*2^n-1 is a prime. %H A050545 Ray Ballinger and Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a> %H A050545 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A050545 <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is a prime</a> %H A050545 Kosmaj, <a href="http://www.15k.org/riesellist.html">Riesel list k<300</a>. %Y A050545 Cf. A002269 = 39*2^n+1 is a prime. %K A050545 hard,nonn %O A050545 1,1 %A A050545 _N. J. A. Sloane_, Dec 29 1999 %E A050545 More terms from _Hugo Pfoertner_, Aug 29 2004 %E A050545 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 02 2008