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A161830
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Y-toothpick triangle (see Comments lines for definition).
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9
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0, 1, 3, 5, 9, 11, 15, 19, 27, 31, 35, 39, 47, 53, 61, 71, 89, 99, 103
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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0,3
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COMMENTS
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Y-toothpick sequence starting at the corner of an infinite hexagon in which its vertex touch an endpoint of the initial Y-toothpick and the two other endpoints are equidistant from the nearest sides of the hexagon.
The sequence gives the number of Y-toothpicks in the structure after n rounds. A161831 (the first differences) gives the number added at the n-th round.
See the Y-toothpick sequence A160120 for more information about the recursive, fractal-like structure.
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LINKS
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CROSSREFS
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KEYWORD
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more,nonn
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AUTHOR
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STATUS
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approved
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