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A194432 D-toothpick sequence starting with a cross formed by 4 toothpicks. 8
0, 4, 12, 28, 44, 60, 88, 136, 168, 184, 216 (list; graph; refs; listen; history; text; internal format)



On the infinite square grid we start with no toothpicks.

At stage 1, we place a cross, centered at the origin, formed by 2 vertical toothpicks and 2 horizontal toothpicks of length 1. At stage 2, we place 8 D-toothpicks of length sqrt(2). At stage 3, we place 16 toothpicks of length 1. And so on.

The sequence gives the number of toothpicks and D-toothpicks in the structure after n-th stage. The first differences (A194433) give the number of toothpicks and D-toothpicks added at n-th stage.

Apparently this cellular automaton has a fractal behavior (or like-fractal behavior) related to power of 2, similar to A194270 and very similar to A194434. The octagonal structure contains a large number of distinct polygonal shapes. For more information see A194270, A194440 and A194442.


Table of n, a(n) for n=0..10.

N. J. A. Sloane, Catalog of Toothpick and Cellular Automata Sequences in the OEIS

Index entries for sequences related to toothpick sequences


Cf. A139250, A194270, A194433, A194434, A194440, A194442.

Sequence in context: A064444 A072182 A009906 * A220512 A194434 A220514

Adjacent sequences:  A194429 A194430 A194431 * A194433 A194434 A194435




Omar E. Pol, Sep 03 2011



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Last modified February 25 16:14 EST 2018. Contains 299653 sequences. (Running on oeis4.)