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 A063791 #12 Sep 18 2024 14:14:15 %S A063791 3,9,13,15,25,49,55,69,115,2071,6249,13669,14215,14625,396127 %N A063791 Numbers k such that 2^(k+1) - k - 2 is prime. %D A063791 Dean Hickerson, personal communication. %F A063791 a(n) = A099439(n) - 1. - _Hugo Pfoertner_, Jul 24 2019 %o A063791 (PARI) for(n=1,5000, if(isprime(2^(n+1)-n-2),print(n))) %Y A063791 Cf. A099439. %K A063791 nonn,more %O A063791 1,1 %A A063791 _Jason Earls_, Aug 17 2001 %E A063791 More terms from Herman Jamke (hermanjamke(AT)fastmail.fm), Jan 03 2008 %E A063791 a(15) from _Karsten Bonath_, Jun 07 2018