A169779 - OEIS

%I #13 Mar 07 2013 20:35:37

%S 1,2,5,6,9,14,21,22,25,30,39,48,55,68,83,84,87,92,101,110,119,136,161,

%T 178,185,198,221,248,267,298,329,330,333,338,347,356,365,382,407,424,

%U 433,450,479,516,549,590,647,680,687,700,723,750,777,820,887,946,973,1004,1059

%N Partial sums of A170898.

%C On the hexagonal grid consider an infinite 60-degree wedge. A cell is turned ON if exactly one of its six neighbors is ON. We start with a single ON cell. An ON cell remains ON forever. The sequence counts the total number of ON states after n generations. The structure is also the tree that arises from one of the six spokes of the structure of A151723. For n >> 1 the structure looks like a quadrilateral formed by two scalene right triangles which are joined at their hypotenuses. - _Omar E. Pol_, Mar 06 2013

%H N. J. A. Sloane, <a href="/A169779/b169779.txt">Table of n, a(n) for n = 0..1023</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/Ce#cell">Index entries for sequences related to cellular automata</a>

%F a(n) = (A151723(n+2) - 1)/6. - _Omar E. Pol_, Mar 06 2013

%Y Cf. A151723, A169780.

%K nonn

%O 0,2

%A _N. J. A. Sloane_, May 10 2010