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 A098231 #11 Sep 08 2022 08:45:14
%S A098231 -7,-3,21,117,2037,8181,131061,524277,8388597,536870901,2147483637,
%T A098231 137438953461,2199023255541,8796093022197,140737488355317,
%U A098231 9007199254740981,576460752303423477,2305843009213693941,147573952589676412917,2361183241434822606837
%N A098231 2^p - 11 for p prime.
%H A098231 Vincenzo Librandi, <a href="/A098231/b098231.txt">Table of n, a(n) for n = 1..200</a>
%e A098231 If p=5, 2^5 - 11 = 21.
%t A098231 Table[2^Prime[n] - 11, {n, 20}]
%o A098231 (Magma) [2^p-11: p in PrimesUpTo(100)]; // _Vincenzo Librandi_, Apr 29 2014
%Y A098231 Cf. A098815.
%K A098231 sign
%O A098231 1,1
%A A098231 _Parthasarathy Nambi_, Oct 25 2004
%E A098231 More terms from _Ray Chandler_, Nov 14 2004