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A230503
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Irregular triangle read by rows: possible number of interior intersection points of the diagonals of an n-sided convex polygon.
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0
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0, 1, 5, 13, 15, 29, 31, 33, 35, 49, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 70
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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3,3
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COMMENTS
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Beginning from number of sides equal to 12 the terms no longer increase between rows. For example, the number of inner diagonal intersection points for the regular 12-gon is fewer than the number of inner diagonal intersection points for regular 11-gon.
Obviously there exists a number k_0 such that k_0 is not in the sequence and k is in the sequence for all k > k_0.
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LINKS
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EXAMPLE
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The beginning of the irregular triangle is:
3| 0
4| 1
5| 5
6| 13, 15
7| 29, 31, 33, 35
8| 49, 52, 53, 54, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 68, 70
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CROSSREFS
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KEYWORD
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tabf,more,nonn
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AUTHOR
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STATUS
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approved
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