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 A050413 #22 Oct 13 2019 02:54:24 %S A050413 0,2552,4892,7896,14352,32124,51476 %N A050413 Numbers k such that 74*2^k-1 is prime. %C A050413 Equals A050544 minus one; A050544 is the main entry for this sequence. - _Jeppe Stig Nielsen_, Oct 09 2019 %D A050413 Computed by Joe K. Crump (joecr(AT)carolina.rr.com) and (mostly) by _David Broadhurst_. %H A050413 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 A050413 Wilfrid Keller, <a href="http://www.prothsearch.com/riesel2.html">List of primes k.2^n - 1 for k < 300</a> %H A050413 <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 A050413 (PARI) is(n)=ispseudoprime(74*2^n-1) \\ _Charles R Greathouse IV_, May 22 2017 %Y A050413 Cf. A050412, A050544. %K A050413 nonn,hard %O A050413 1,2 %A A050413 _David Broadhurst_, Dec 22 1999 %E A050413 _David Broadhurst_, Dec 26 1999 reports that primality up to n=51476 is now proved, using Yves Gallot's proth.exe.