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 A160785 #10 Feb 27 2014 01:39:50 %S A160785 3,7,11,15,23,27,31,35,39,43,47,59,63,67,71,75,79,83,87,95,103,107, %T A160785 111,115,119,123,131,135,139,143,147,155,159,167,171,175,179,183,187, %U A160785 191,195,203,207,211,215,219,223,227,231,239,247,255,259,263,267,275,279 %N A160785 Even squarefree numbers plus 1. %F A160785 a(n) = A039956(n) + 1. %e A160785 10 is an even squarefree number, so 11 is in this list. %p A160785 with(numtheory): a := proc (n) if issqrfree(2*n) = true then 2*n+1 else end if end proc: seq(a(n), n = 1 .. 150); # _Emeric Deutsch_, Jun 20 2009 %Y A160785 Cf. A005117. %K A160785 easy,nonn %O A160785 1,1 %A A160785 _Ben Paul Thurston_, May 26 2009 %E A160785 More terms from _Emeric Deutsch_, Jun 20 2009