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 A032356 #40 Dec 21 2024 09:46:38 %S A032356 2,8,10,20,28,82,188,308,316,1000,28280,38008,43856,88018,109258, %T A032356 114296,521306,562456,684560,1038896,1499876,1861732,4998362,5523860, %U A032356 6481780,8989858 %N A032356 Numbers k such that 13*2^k+1 is prime. %H A032356 Ray Ballinger, <a href="http://www.prothsearch.com/index.html">Proth Search Page</a> %H A032356 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 A032356 Y. Gallot, <a href="http://www.utm.edu/research/primes/programs/gallot/index.html">Proth.exe: Windows Program for Finding Large Primes</a> %H A032356 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A032356 <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> %t A032356 Select[Range[1000], PrimeQ[13*2^#+1] &] (* _Amiram Eldar_, Dec 12 2018 *) %o A032356 (PARI) is(n)=ispseudoprime(13*2^n+1) \\ _Charles R Greathouse IV_, May 22 2017 %Y A032356 Cf. A002257. %K A032356 nonn,hard,more %O A032356 1,1 %A A032356 _James R. Buddenhagen_ %E A032356 Added more terms (from http://web.archive.org/web/20161028080239/http://www.prothsearch.net/riesel.html), _Joerg Arndt_, Apr 07 2013 %E A032356 a(23) from http://www.prothsearch.com/riesel1.html by _Robert Price_, Dec 12 2018 %E A032356 a(24) from _Jeppe Stig Nielsen_, Jan 24 2020 %E A032356 a(25)-a(26) from _Jeppe Stig Nielsen_, Dec 21 2024