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 A062361 Number of triangular regions in regular n-gon with all diagonals drawn. 19
 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; text; internal format)
 OFFSET 3,2 COMMENTS Also the number of 3-cycles and maximum cliques in the n-polygon diagonal intersection graph. - Eric W. Weisstein, Mar 08-09 2018 LINKS Andrew Howroyd, Table of n, a(n) for n = 3..100 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. Eric Weisstein's World of Mathematics, Graph Cycle Eric Weisstein's World of Mathematics, Maximum Clique Eric Weisstein's World of Mathematics, Polygon Diagonal Intersection Graph FORMULA a(n) = n * A067162(n). EXAMPLE a(4) = 4 because in a quadrilateral the diagonals cross to make four triangles. CROSSREFS Cf. A006600, A007678. Cf. A300552 (4-cycles), A300553 (5-cycles), A300554 (6-cycles). Sequence in context: A225610 A009921 A050188 * A038416 A217745 A213949 Adjacent sequences:  A062358 A062359 A062360 * A062362 A062363 A062364 KEYWORD easy,nonn AUTHOR Sascha Kurz, Jul 07 2001 STATUS approved

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Last modified June 15 17:41 EDT 2021. Contains 345049 sequences. (Running on oeis4.)