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 A266536 #20 Oct 10 2022 09:37:51 %S A266536 0,1,2,3,6,7,10,13,16,21,24,29,36,39,42,45,50,57,62,71,80,91,102,111, %T A266536 124,137,144,151,158,167,178,189,206,223,242,261,276,293,310,327,344, %U A266536 359,368,385,402,423,448,467,486,509,526,547,570,595,630,655,688,717,742,763,782,809,844,871,896,921,954,977,1016,1059 %N A266536 Total number of ON cells after n-th stage in a 90-degree sector of the cellular automaton of A170896. %C A266536 The structure looks like a tree which arises from one of the four spokes of the structure of the cellular automaton of A170896. %C A266536 a(n) is the total number of ON cells after n-th stage. %C A266536 For n >> 1 the structure looks like a square which is rotated 45 degrees. %C A266536 First differs from both A161336 (snowflake tree) and A266534 at a(13). %H A266536 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 A266536 <a href="/index/Ce#cell">Index entries for sequences related to cellular automata</a> %H A266536 <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a> %F A266536 a(n) = (A170896(n+1) - 1)/4. %Y A266536 Cf. A161336, A169779, A170896, A266534, A267700. %K A266536 nonn %O A266536 0,3 %A A266536 _Omar E. Pol_, Jan 12 2016