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 A253768 #17 Oct 04 2018 09:57:19
%S A253768 1,3,6,10,19,27,42,56,61,67,92,104,139,155,162,172,193,213,240,262,
%T A253768 301,312,325,358,384,429,457,508,540,557,575,660,684,739,773,838,874,
%U A253768 965,995,1044,1082,1145,1164,1206,1301,1345,1402,1442,1511,1561,1584,1632,1747,1799,1874,1920,2001,2057,2144,2206
%N A253768 Partial sums of A098550.
%C A253768 For the partial sums of EKG sequence see A065057.
%H A253768 David L. Applegate, Hans Havermann, Bob Selcoe, Vladimir Shevelev, N. J. A. Sloane, and Reinhard Zumkeller, <a href="http://arxiv.org/abs/1501.01669">The Yellowstone Permutation</a>, arXiv preprint arXiv:1501.01669, 2015.
%t A253768 f[lst_] := Block[{k = 4}, While[GCD[lst[[-2]], k] == 1 || GCD[lst[[-1]], k] > 1 || MemberQ[lst, k], k++]; Append[lst, k]];
%t A253768 Nest[f, {1, 2, 3}, 68] // Accumulate (* _Jean-François Alcover_, Oct 04 2018, after _Robert G. Wilson v_ *)
%Y A253768 Cf. A065057, A098550, A250299, A253765, A253766.
%K A253768 nonn
%O A253768 1,2
%A A253768 _Omar E. Pol_, Jan 27 2015