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 A087572 #4 Dec 05 2013 19:56:31 %S A087572 0,2,3,7,5,11,7,0,17,19,11,23,13,0,29,31,17,0,19,0,41,43,23,47,0,0,53, %T A087572 0,29,59,31,0,0,67,0,71,37,0,0,79,41,83,43,0,89,0,47,0,97,0,101,103, %U A087572 53,107,109,0,113,0,59,0,61,0,0,127,0,131,67,0,137,139,71,0,73,0,149,151,0 %N A087572 Smallest prime of the form n + (n-1) + (n-2) + ...(n-k), k < n, or 0 if no such prime exists. %C A087572 Trivially a(n) = 0 if n and 2n-1 both are composite. i.e. (k = 0 or 1.) %C A087572 If a(n) > 0 then a(n) = A034694(n-1). - _David Wasserman_, Jun 07 2005 %K A087572 nonn %O A087572 1,2 %A A087572 _Amarnath Murthy_, Sep 17 2003 %E A087572 More terms from _David Wasserman_, Jun 07 2005