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 A160800 #10 Feb 24 2021 02:48:18 %S A160800 0,1,3,7,9,10,12,15,16,17,19,22,25,28,33,38,40,41,43,46,48,50,54,60, %T A160800 65,68,73,78,80,82,86,92,93,95,98,100,102,106,112,117,120,125,130,132, %U A160800 134,138,144,149,153,160,168,174,182,196 %N A160800 Toothpick sequence in Fibonacci spiral (see Comments lines for definition). %C A160800 On the infinite square grid we draw a Fibonacci spiral starting with 2,2,4,6,10,16,... (Note that each edge has length = A000045(k)*2, for k>0). We start at stage 0 with no toothpicks. At stage 1 we place a toothpick in a orthogonal direction, in the center of the Fibonacci spiral. At stage 2 we place 2 toothpicks. And so on... %C A160800 The sequence gives the number of toothpicks in the Fibonacci spiral after n stages. A160801 (the first differences) gives the number added at the n-th stage. See A139250 for more information about toothpick sequences. %H A160800 Nathaniel Johnston, <a href="/A160800/b160800.txt">Table of n, a(n) for n = 0..255</a> %H A160800 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 A160800 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> %H A160800 Nathaniel Johnston, <a href="/A160800/a160800.c.txt">C script for computing terms</a> %Y A160800 Cf. A000045, A139250, A139251, A160426, A160427. %K A160800 nonn %O A160800 0,3 %A A160800 _Omar E. Pol_, May 26 2009 %E A160800 Terms after a(32) from _Nathaniel Johnston_, Mar 30 2011