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 A169799 #12 Feb 18 2019 11:23:38 %S A169799 1,3,6,7,12,15,23,24,26,31,32,35,36,37,41,42,49,51,52,53,55,56,59,60, %T A169799 64,65,69,70,72,75,76,79,80,82,85,86,93,94,97,99,102,106,109,110,112, %U A169799 122,123,125,126,128,130,133,137,141,143,145,150,153,154,157,166,168,172,173,174,178,185,188,193,195,199,200 %N A169799 First differences of A167209. %H A169799 K. S. Brown, <a href="http://www.mathpages.com/home/kmath509/kmath509.htm">Expulsion Sets</a> %Y A169799 Cf. A167209, A169820. %K A169799 nonn %O A169799 1,2 %A A169799 _N. J. A. Sloane_, Sep 03 2014 %E A169799 Definition changed because of new offset in A167209. - _N. J. A. Sloane_, Feb 18 2019