Comments and References for A000332 and A000579

[Antreas P. Hatzipolakis]

Find the number of intersections of the diagonals of a convex polygon of
n sides.

Answer:  C(n,4)
(In EIS A000332)

References:
Norbert Kaufman and R. H. Koch, AMM, 54 (June, 1947), p. 344
Charles W. Trigg: Mathematical Quickies.
New York: Dover Publications, Inc., 1985, p. 53, #191

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If n points on the circumference of a circle are joined by straight lines
in all possible ways, and no three of these lines meet at a single point
inside the circle, find the number of triangles formed, all of whose
vertices lie inside the circle.

Answer:  C(n,6)
(In EIS: A000579)

References:
Leo Moser, Mathematics Magazine, 26 (March, 1953), p. 226.
Charles W. Trigg: Mathematical Quickies.
New York: Dover Publications, Inc., 1985, p. 11, #32

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Antreas