A240439 - cp's OEIS frontend

A240439 Triangle T(n, k) = Numbers of ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle of any orientation. Triangle read by rows.

n	a(n)
1	1
2	1
3	1
4	3
5	3
6	1
7	6
8	15
9	15
10	3
11	1
12	10
13	45
14	105
15	114
16	39
17	3
18	1
19	15
20	105
21	420
22	969
23	1194
24	654
25	102
26	3
27	1
28	21
29	210
30	1260
31	4773
32	11259
33	15615
34	11412
35	3663
36	342
37	15
38	1
39	28
40	378
41	3150
42	17415
43	64776
44	159528
45	250233
46	234609
47	119259
48	28395
49	2613
50	69
51	1
52	36
53	630
54	6930

[1, 1, 1, 3, 3, 1, 6, 15, 15, 3, 1, 10, 45, 105, 114, 39, 3, 1, 15, 105, 420, 969, 1194, 654, 102, 3, 1, 21, 210, 1260, 4773, 11259, 15615, 11412, 3663, 342, 15, 1, 28, 378, 3150, 17415, 64776, 159528, 250233, 234609, 119259, 28395, 2613, 69, 1, 36, 630, 6930]

cp's OEIS Frontend

A240439 Triangle T(n, k) = Numbers of ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle of any orientation. Triangle read by rows.

Table of values

List of values