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 A032419 #32 Dec 20 2018 10:32:24 %S A032419 2,14,914,12614,335522,1567874 %N A032419 Numbers k such that 139*2^k + 1 is prime. %H A032419 Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a> %H A032419 Ray Ballinger & Wilfrid Keller, <a href="http://www.prothsearch.com/riesel1.html">List of primes k.2^n + 1 for k < 300</a>. %H A032419 Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a> %H A032419 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A032419 <a href="/index/Pri#riesel">Index entries for sequences of n such that k*2^n-1 (or k*2^n+1) is prime</a> %p A032419 select(k->isprime(139*2^k+1),[$0..1000])[]; # _Muniru A Asiru_, Dec 18 2018 %t A032419 Select[Range[1000], PrimeQ[139*2^# + 1] & ] (* _Robert Price_, Dec 18 2018 *) %o A032419 (PARI) is(n)=ispseudoprime(139*2^n+1) \\ _Charles R Greathouse IV_, Jun 07 2017 %Y A032419 Cf. A032418, A032373, A032420, A032460, A032497. %K A032419 nonn,hard,more %O A032419 1,1 %A A032419 _James R. Buddenhagen_ %E A032419 One more term (from the Ballinger-Keller web page) from _M. F. Hasler_, Apr 18 2007 %E A032419 a(6) from the Ray Ballinger and Wilfrid Keller link by _Robert Price_, Dec 18 2018