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 A032359 #32 Oct 31 2020 04:49:29 %S A032359 6,10,46,366,1246,2038,4386,4438,6838,7498,7998,9450,11890,17034, %T A032359 23290,73338,149146,323638,853546,2206266,6833086 %N A032359 Numbers k such that 19*2^k+1 is prime. %H A032359 Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a> %H A032359 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 A032359 Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a> %H A032359 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A032359 <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> %o A032359 (PARI) is(n)=ispseudoprime(19*2^n+1) \\ _Charles R Greathouse IV_, Jun 06 2017 %K A032359 nonn,hard %O A032359 1,1 %A A032359 _James R. Buddenhagen_ %E A032359 Added more terms (from http://www.prothsearch.com/riesel1.html), _Joerg Arndt_, Apr 07 2013 %E A032359 a(21) from _Jeppe Stig Nielsen_, Oct 30 2020