A243141 - cp's OEIS frontend

A243141 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 of any orientation. 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	19
11	22
12	7
13	1
14	4
15	22
16	75
17	170
18	204
19	115
20	18
21	1
22	5
23	41
24	218
25	816
26	1891
27	2635
28	1909
29	628
30	58
31	3
32	7
33	72
34	542
35	2947
36	10846
37	26695
38	41770
39	39218
40	19905
41	4776
42	437
43	13
44	8
45	116
46	1178
47	8765
48	46068
49	171700
50	444117
51	776276
52	876012
53	601078
54	229941

[1, 1, 1, 2, 4, 3, 1, 3, 10, 19, 22, 7, 1, 4, 22, 75, 170, 204, 115, 18, 1, 5, 41, 218, 816, 1891, 2635, 1909, 628, 58, 3, 7, 72, 542, 2947, 10846, 26695, 41770, 39218, 19905, 4776, 437, 13, 8, 116, 1178, 8765, 46068, 171700, 444117, 776276, 876012, 601078, 229941]

cp's OEIS Frontend

A243141 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 of any orientation. Triangle read by rows.

Table of values

List of values