11,19

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.

Table of n, a(n) for n=11..109.

Sascha Kurz, m-gons in regular n-gons

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).

Sequences formed by drawing all diagonals in regular polygon

a(11)=1 because drawing the regular 11-gon with all its diagonals yields 1 11-gon.

Cf. A007678, A064869, A067151, A067152, A067153, A067154, A067155, A067156, A067157, A067159.

Sequence in context: A137942 A099090 A123269 * A243001 A092995 A040847

Adjacent sequences: A067155 A067156 A067157 * A067159 A067160 A067161

easy,nonn

Sascha Kurz, Jan 06 2002

approved