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A062361
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Number of triangular regions in regular n-gon with all diagonals drawn.
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1
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1, 4, 10, 18, 35, 56, 90, 120, 176, 276, 377, 476, 585, 848, 1054, 1404, 1653, 2200, 2268, 2992, 3749, 4416, 5000, 6292, 6777, 8316, 9222, 11670, 11501, 14368, 15840, 18598, 19705, 24444, 25012, 28842, 30966, 36000, 39278, 45318, 46999, 53900
(list; graph; refs; listen; history; internal format)
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OFFSET
| 3,2
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LINKS
| B. Poonen and M. Rubinstein, Number of Intersection Points Made by the Diagonals of a Regular Polygon, SIAM J. Discrete Mathematics, Vol. 11, pp. 135-156.
B. Poonen and M. Rubinstein, The number of intersection points made by the diagonals of a regular polygon, SIAM J. on Discrete Mathematics, Vol. 11, No. 1, 135-156 (1998).
S. E. Sommars and T. Sommars, Number of Triangles Formed by Intersecting Diagonals of a Regular Polygon, J. Integer Sequences, 1 (1998), #98.1.5.
Sequences formed by drawing all diagonals in regular polygon
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FORMULA
| a(n) = n * A067162(n).
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EXAMPLE
| a(4) = 4 because in a quadrilateral the diagonals cross to make four triangles.
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CROSSREFS
| Cf. A006600, A007678.
Sequence in context: A073839 A009921 A050188 * A038416 A009913 A063591
Adjacent sequences: A062358 A062359 A062360 * A062362 A062363 A062364
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KEYWORD
| easy,nonn
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AUTHOR
| S. Kurz (sascha.kurz(AT)uni-bayreuth.de), Jul 07 2001
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