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 A091010 #3 Mar 30 2012 18:50:43 %S A091010 1,2,3,4,5,7,8,9,10,11,13,14,16,17,19,20,21,22,23,25,26,27,29,31,32, %T A091010 33,34,35,37,38,39,41,43,44,46,47,49,50,51,52,53,55,57,58,59,61,62,63, %U A091010 64,65,67,68,69,70,71,73,74,76,77,79,81,82,83,85,86,87,88,89,92,93,94 %N A091010 Numbers having no divisor d such that also d-x and d+x are divisors for some x. %C A091010 A091009(a(n)) = 0; complement of A091011. %K A091010 nonn %O A091010 1,2 %A A091010 _Reinhard Zumkeller_, Dec 13 2003