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 A170886 #9 Feb 24 2021 02:48:19 %S A170886 0,1,3,5,7,11,17,23,29,37,49,55,63,75,93,107,121,141,161,167,175,187, %T A170886 205,219,235,259,285,301,325,363,409,447,489,541,577,583,591,603,621, %U A170886 635,651,675,701,717,741,779,825,863,907,963,1005,1021,1045,1083,1129 %N A170886 Similar to A160406, but always staying outside the wedge, starting at stage 1 with a toothpick whose midpoint touches the vertex of the wedge. %C A170886 See A170887 for the first differences. %H A170886 David Applegate, Omar E. Pol and N. J. A. Sloane, <a href="/A000695/a000695_1.pdf">The Toothpick Sequence and Other Sequences from Cellular Automata</a>, Congressus Numerantium, Vol. 206 (2010), 157-191. [There is a typo in Theorem 6: (13) should read u(n) = 4.3^(wt(n-1)-1) for n >= 2.] %H A170886 N. J. A. Sloane, <a href="/wiki/Catalog_of_Toothpick_and_CA_Sequences_in_OEIS">Catalog of Toothpick and Cellular Automata Sequences in the OEIS</a> %Y A170886 Cf. A139250, A170887, A170888, A170890, A170892. %K A170886 nonn %O A170886 0,3 %A A170886 _Omar E. Pol_, Jan 09 2010 %E A170886 Terms beyond a(9) from _R. J. Mathar_, Jan 25 2010