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A187213 Number of Q-toothpicks added at n-th stage to the structure of A187212.

%I A187213 #17 Feb 24 2021 02:48:19
%S A187213 0,1,2,2,4,4,8,10,8,4,8,12,12,16,28,30,16,4,8,12,12,16,28,32,20,16,28,
%T A187213 36,40,60,88,78,32,4,8,12,12,16,28,32,20,16,28,36,40,60,88,80,36,16,
%U A187213 28,36,40,60,88,84,56,60,92,112
%N A187213 Number of Q-toothpicks added at n-th stage to the structure of A187212.
%C A187213 Essentially the first differences of A187212.
%H A187213 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 A187213 Nathaniel Johnston, <a href="http://www.nathanieljohnston.com/2011/03/the-q-toothpick-cellular-automaton/">The Q-Toothpick Cellular Automaton</a>
%H A187213 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 A187213 It appears that if n = 2^k - 1, for k >= 2, then a(n) = A139251(n) - 2 otherwise a(n) = A139251(n). - Omar E. Pol, Mar 30 2011
%e A187213 Contribution from Omar E. Pol, Mar 29 2011 (Start):
%e A187213 If written as a triangle begins:
%e A187213 0,
%e A187213 1,
%e A187213 2,
%e A187213 2,4,
%e A187213 4,8,10,8,
%e A187213 4,8,12,12,16,28,30,16,
%e A187213 4,8,12,12,16,28,32,20,16,28,36,40,60,88,78,32,
%e A187213 (End)
%Y A187213 Cf. A139250, A139251, A187211, A187212, A187221.
%K A187213 nonn
%O A187213 0,3
%A A187213 _Omar E. Pol_, Mar 22 2011
%E A187213 Terms after a(24) from _Nathaniel Johnston_, Mar 28 2011