A220522 - OEIS

%I #20 Mar 11 2014 01:34:21

%S 0,1,3,7,11,15,19,26,34,38,42,50,62,70,78,91,107,111,115,123,135,151,

%T 167,187,211,223,231,247,275,291,307,332,364,368,372,380,392,408,424,

%U 446,478,504,524,548,588,620,660,701,749,769,777

%N Number of toothpicks and D-toothpicks after n-th stage in the D-toothpick "narrow" triangle of the third kind.

%C The structure is essentially one of the oblique wedges of several D-toothpick structures. For more information see A220500. First differs from A194442 at a(47). The first differences (A220523) give the number of toothpicks or D-toothpicks added at n-th stage.

%H Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poltp064.jpg">Illustration of the structure after 32 stages</a>

%H Omar E. Pol, <a href="http://www.polprimos.com/imagenespub/poltp068.jpg">Illustration of the structure after 64 stages</a>

%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>

%H <a href="/index/To#toothpick">Index entries for sequences related to toothpick sequences</a>

%Y Cf. A047999, A139250, A194270, A194700, A194440, A194442, A194444, A220496, A220500, A220523.

%K nonn

%O 0,3

%A _Omar E. Pol_, Dec 15 2012