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 A098856 #15 Aug 17 2024 23:01:46 %S A098856 1,3,19,34,51,318,3670,6348,33292,48582,50235,50964 %N A098856 Numbers k such that 4^k*(2^k - 1) + 1 is a prime. %C A098856 a(9) > 11500. - _Jinyuan Wang_, Mar 19 2020 %o A098856 (Magma) [k: k in [1..500] | IsPrime(4^k*(2^k-1)+1)]; // _Jinyuan Wang_, Mar 19 2020 %Y A098856 Cf. A098857 ((4^k)*(2^k - 1) - 1 is prime). %K A098856 nonn,more %O A098856 1,2 %A A098856 _Pierre CAMI_, Oct 11 2004 %E A098856 6348, corresponding to a probable prime, from _Ryan Propper_, Jun 18 2005 %E A098856 Edited by _T. D. Noe_, Oct 30 2008 %E A098856 a(9)-a(12) from _Michael S. Branicky_, Aug 17 2024