A192314 - cp's OEIS frontend

A192314 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 nonempty subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=0, a(2)=1 by convention.

n	a(n)
1	0
2	1
3	3
4	21
5	207
6	5559
7	299599
8	33562695
9	7635498335
10	3518440564543
11	3275345183542207
12	6148914696963883711
13	23248573454127484129023
14	176848577040808821410837119
15	2704321280486889389864215362559
16	83076749736557243209409446411255935
17	5124252113632955685095523500148980125695
18	634332307869315502692705867068871886072665599
19	157534492276509956656902449336997243381860518317055

[0, 1, 3, 21, 207, 5559, 299599, 33562695, 7635498335, 3518440564543, 3275345183542207, 6148914696963883711, 23248573454127484129023, 176848577040808821410837119, 2704321280486889389864215362559, 83076749736557243209409446411255935, 5124252113632955685095523500148980125695, 634332307869315502692705867068871886072665599, 157534492276509956656902449336997243381860518317055]

cp's OEIS Frontend

A192314 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 nonempty subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=0, a(2)=1 by convention.

Table of values

List of values

cp's OEIS Frontend

A192314 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 nonempty subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=0, a(2)=1 by convention.

Table of values

List of values

A192314 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 nonempty subset of these lines (subsets differing by a rotation are regarded as identical). a(1)=0, a(2)=1 by convention.