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 A215434 #16 Sep 08 2022 08:46:03
%S A215434 2,7,31,1123,1180591620717411308323,
%T A215434 21778071482940061661655974875633165551139,
%U A215434 89202980794122492566142873090593446023942979,1569275433846670190958947355801916604025588861116008664323
%N A215434 Primes of form 2^k + k^2 - 1.
%H A215434 Vincenzo Librandi, <a href="/A215434/b215434.txt">Table of n, a(n) for n = 1..11</a>
%t A215434 Select[Table[2^n + n^2 - 1, {n, 0, 300}], PrimeQ]
%o A215434 (Magma) [a: n in [0..250] | IsPrime(a) where a is 2^n+n^2-1];
%Y A215434 Cf. A035325, A061119, A215439.
%K A215434 nonn,easy
%O A215434 1,1
%A A215434 _Vincenzo Librandi_, Sep 03 2012