A160809 - OEIS

%I #10 Feb 24 2021 02:48:18

%S 1,2,4,4,4,8,12,4,1,2,3,3,4,7,8,1,2,3,3,4,5,7,5,3,5,7,8,11,13,17,12,4,

%T 5,8,7,9,5,7,9,8,4,8,8,7,8,13,14,10,8,12,11,13,13,17,16,11,8,15,13,14,

%U 19,26,21,5,7

%N First differences of A160808.

%C Number of toothpicks added to the spiral at the n-th stage.

%H Nathaniel Johnston, <a href="/A160809/b160809.txt">Table of n, a(n) for n = 1..254</a>

%H 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 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 Cf. A000045, A139250, A139251, A160426, A160427, A160800, A160801, A160802, A160803, A160808.

%K nonn

%O 1,2

%A _Omar E. Pol_, May 26 2009

%E Terms after a(16) from _Nathaniel Johnston_, Mar 30 2011