

A233780


Number of toothpicks and Dtoothpicks after nth stage in a Dtoothpick "wide" triangle (see Comments lines for definition).


6



0, 1, 3, 5, 9, 11, 15, 21, 29, 31, 35, 41, 51, 61, 69, 83, 99, 101, 105, 111, 121, 131, 141, 159, 183, 201, 209, 223, 245, 271, 287, 317, 349, 351, 355, 361, 371, 381, 391, 409, 433, 451, 461, 479, 509, 547, 573, 615, 667, 701, 709, 723, 745, 771
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,3


COMMENTS

The Dtoothpicks placed in northwest or northeast direction both are prohibited, except in the substructures in which the symmetry could be broken, so a(44) = 509, not 507. For another version with broken symmetry in some substructures see A233764. See also A231348, a simpler cellular automaton based in triangles which has essentially a similar structure.
A233781 (the first differences) gives the number of toothpicks or Dtoothpicks added at nth stage.
First differs from A169780 at a(24).
First differs from A233970 at a(25).
First differs from A233764 at a(44).


LINKS

Table of n, a(n) for n=0..53.
N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS
Index entries for sequences related to toothpick sequences


CROSSREFS

Cf. A139250, A169780, A220500, A231348, A233764, A233781, A233970.
Sequence in context: A261141 A283594 A233764 * A233970 A169780 A233760
Adjacent sequences: A233777 A233778 A233779 * A233781 A233782 A233783


KEYWORD

nonn


AUTHOR

Omar E. Pol, Dec 15 2013


STATUS

approved



