A243207 - cp's OEIS frontend

A243207 Triangle T(n, k) = Numbers of inequivalent (mod D_3) ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle with sides parallel to the grid. Triangle read by rows.

n	a(n)
1	1
2	1
3	1
4	2
5	4
6	3
7	1
8	3
9	10
10	20
11	25
12	11
13	3
14	4
15	22
16	77
17	186
18	266
19	221
20	86
21	14
22	5
23	41
24	223
25	881
26	2344
27	4238
28	4885
29	3451
30	1296
31	220
32	7
33	1
34	7
35	72
36	552
37	3146
38	12907
39	38640
40	83107
41	126701
42	132236
43	90214
44	37128
45	8235
46	775
47	24
48	8
49	116
50	1196
51	9264
52	53307
53	232861
54	773930

[1, 1, 1, 2, 4, 3, 1, 3, 10, 20, 25, 11, 3, 4, 22, 77, 186, 266, 221, 86, 14, 5, 41, 223, 881, 2344, 4238, 4885, 3451, 1296, 220, 7, 1, 7, 72, 552, 3146, 12907, 38640, 83107, 126701, 132236, 90214, 37128, 8235, 775, 24, 8, 116, 1196, 9264, 53307, 232861, 773930]

cp's OEIS Frontend

A243207 Triangle T(n, k) = Numbers of inequivalent (mod D_3) ways to place k points on a triangular grid of side n so that no three of them are vertices of an equilateral triangle with sides parallel to the grid. Triangle read by rows.

Table of values

List of values