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 A138325 #5 Mar 30 2012 17:22:47 %S A138325 0,0,2,0,3,0,5,5,0,7,0,7,11,0,13,0,11,11,11,13,19,17,17,13,0,0,17,17, %T A138325 17,23,17,19,19,19,0,0,23,23,29,23,0,23,23,23,0,43,29,29,0,29,0,31,31, %U A138325 37,29,29,37,41,37,41,37,43,41,0,41,47,41,61,37,41,41,37,43,53,41,41,43,47 %N A138325 Least prime p such that n = p + g, where g is a primitive root of p, or 0 if there is no such prime p. %C A138325 Sequence A138128 gives the number of representations for each n and sequence A138326 lists the values of n that are not represented. %H A138325 T. D. Noe, <a href="/A138325/b138325.txt">Table of n, a(n) for n=1..1000</a> %Y A138325 Cf. A060749 (primitive roots). %K A138325 nonn %O A138325 1,3 %A A138325 _T. D. Noe_, Mar 14 2008