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 A191840 #11 Feb 14 2014 00:21:43
%S A191840 0,1,2,3,4,5,7,8,9,11,13,14,15,18,21,23,24,25,29,34,37,39,40,41,47,55,
%T A191840 60,63,65,66,67,76,89,97,102,105,107,108,109,123,144,157,165,170,173,
%U A191840 175,176,177,199,233,254,267,275,280,283,285,286,287,322,377
%N A191840 Ordered sequence of nonnegative differences 2*f-g, where f and g are positive Fibonacci numbers (A000045).
%t A191840 (See A191838.)
%t A191840 Union[Select[2First[#]-Last[#]&/@Tuples[Fibonacci[Range[20]], {2}], #>=0&]] (* _Harvey P. Dale_, Jun 19 2011 *)
%Y A191840 Cf. A191838, A191839, A191841.
%K A191840 nonn
%O A191840 1,3
%A A191840 _Clark Kimberling_, Jun 17 2011