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 A120068 #6 Sep 07 2012 15:22:59 %S A120068 1,3,6,10,12,13,18,21,26,29,30,33,37,40,42,44,50,55,59,60,65,66,71,74, %T A120068 77,78,79,80,82,84,88,89,97,100,104,110,112,113,116,119,121,122,123, %U A120068 127,130,134,135,136,139,142,145,147,148,151,158,159,160,165,168,169,172 %N A120068 Numbers n such that n-th prime + 1 is squarefree. %H A120068 Harvey P. Dale, <a href="/A120068/b120068.txt">Table of n, a(n) for n = 1..1000</a> %F A120068 a(n)=primepi(A049097(n)) %t A120068 Select[Range[200],SquareFreeQ[Prime[#]+1]&] (* _Harvey P. Dale_, Sep 07 2012 *) %Y A120068 Cf. A049097. %K A120068 nonn %O A120068 1,2 %A A120068 _Zak Seidov_, Aug 15 2006