A192332 - cp's OEIS frontend

A192332 For n >= 3, draw a regular n-sided polygon and its n(n-3)/2 diagonals, so there are n(n-1)/2 lines; a(n) is the number of ways to choose a subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=1, a(2)=2 by convention.

n	a(n)
1	1
2	2
3	4
4	22
5	208
6	5560
7	299600
8	33562696
9	7635498336
10	3518440564544
11	3275345183542208
12	6148914696963883712
13	23248573454127484129024
14	176848577040808821410837120
15	2704321280486889389864215362560
16	83076749736557243209409446411255936
17	5124252113632955685095523500148980125696
18	634332307869315502692705867068871886072665600

[1, 2, 4, 22, 208, 5560, 299600, 33562696, 7635498336, 3518440564544, 3275345183542208, 6148914696963883712, 23248573454127484129024, 176848577040808821410837120, 2704321280486889389864215362560, 83076749736557243209409446411255936, 5124252113632955685095523500148980125696, 634332307869315502692705867068871886072665600]

cp's OEIS Frontend

A192332 For n >= 3, draw a regular n-sided polygon and its n(n-3)/2 diagonals, so there are n(n-1)/2 lines; a(n) is the number of ways to choose a subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=1, a(2)=2 by convention.

Table of values

List of values