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 A020484 #13 Apr 21 2015 11:34:45 %S A020484 2,5,7,11,11,13,17,17,19,23,23,29,29,29,31,37,37,37,41,41,43,47,47,53, %T A020484 53,53,59,59,59,61,67,67,67,71,71,73,79,79,79,83,83,89,89,89,101,97, %U A020484 97,97,101,101,103,107,107,109,113,113,131,127,127,131,127,127,127,131,131,137 %N A020484 Least prime p such that there exists a prime q with p-2n = q. %H A020484 Reinhard Zumkeller, <a href="/A020484/b020484.txt">Table of n, a(n) for n = 0..10000</a> %o A020484 (Haskell) %o A020484 a020484 n = head [q | p <- a000040_list, let q = p + 2*n, a010051' q == 1] %o A020484 -- _Reinhard Zumkeller_, Nov 29 2014 %Y A020484 Cf. A000040, A010051, A020483. %K A020484 nonn %O A020484 0,1 %A A020484 _David W. Wilson_ %E A020484 Minor edits by _N. J. A. Sloane_, Jul 13 2010