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 A174262 #4 Mar 30 2012 18:40:08 %S A174262 23,443,194483 %N A174262 Primes of the form 21^(2^n) + 2. %C A174262 a(n) is congruent 3 mod 4. %C A174262 The next term (if it exists) corresponds to some n>23, so it has more than 11 million digits. [R. J. Mathar, Aug 23 2010] %Y A174262 Cf. A057726, A152589. %K A174262 nonn,bref %O A174262 1,1 %A A174262 _Giovanni Teofilatto_, Mar 14 2010 %E A174262 Entries checked. - _R. J. Mathar_, Aug 23 2010