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 A233780 Number of toothpicks and D-toothpicks after n-th stage in a D-toothpick "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 D-toothpicks 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 D-toothpicks added at n-th stage. First differs from A169780 at a(24). First differs from A233970 at a(25). First differs from A233764 at a(44). LINKS N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS 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

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Last modified April 25 21:06 EDT 2019. Contains 322461 sequences. (Running on oeis4.)