A334712 - cp's OEIS frontend

A334712 Number of ways to select four points from an n X n grid so that three of them form a triangle of nonzero area and the extra point is strictly inside the triangle.

n	a(n)
1	0
2	0
3	8
4	240
5	2100
6	11604
7	45184
8	145648
9	399656
10	976552
11	2172328
12	4500816
13	8736172
14	16135996
15	28493760
16	48400296
17	79500936
18	126909720
19	197253768
20	299683032
21	445664700
22	650291092
23	932742112
24	1317391344
25	1833532544
26	2518622024
27	3417812896
28	4585946096
29	6088659404
30	8006284316
31	10430982968
32	13476148160

[0, 0, 8, 240, 2100, 11604, 45184, 145648, 399656, 976552, 2172328, 4500816, 8736172, 16135996, 28493760, 48400296, 79500936, 126909720, 197253768, 299683032, 445664700, 650291092, 932742112, 1317391344, 1833532544, 2518622024, 3417812896, 4585946096, 6088659404, 8006284316, 10430982968, 13476148160]

cp's OEIS Frontend

A334712 Number of ways to select four points from an n X n grid so that three of them form a triangle of nonzero area and the extra point is strictly inside the triangle.

Table of values

List of values