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 A188346 #20 Feb 24 2021 02:48:19 %S A188346 0,0,0,0,0,2,4,4,4,8,12,12,12,16,20,20,28,44,52,52,52,56,60,60,68,84, %T A188346 92,92,96,108,116,124,156,196,212,212,212,216,220,220,228,244,252,252, %U A188346 256,268,276,284,316,356,372,372,376,388,396 %N A188346 Number of hearts present in the n-th generation of the Q-toothpick sequence A187210. %C A188346 See A187210 for a description of the different shapes that appear in the Q-toothpick sequence. %H A188346 Nathaniel Johnston, <a href="/A188346/b188346.txt">Table of n, a(n) for n = 0..181</a> %H A188346 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 A188346 Nathaniel Johnston, <a href="http://www.nathanieljohnston.com/2011/03/the-q-toothpick-cellular-automaton/">The Q-Toothpick Cellular Automaton</a> %H A188346 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> %F A188346 It appears that a(n) = A211008(n-2,2), n >= 3. (Checked by hand up n = 130 in the toothpick structure of A139250). - _Omar E. Pol_, Sep 25 2012 %Y A188346 Cf. A187210, A188344, A188345. %K A188346 nonn %O A188346 0,6 %A A188346 _Nathaniel Johnston_, Mar 28 2011