A226290 - cp's OEIS frontend

A226290 Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (3,n)-rectangular grid with k '1's and (3n-k) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other.

n	a(n)
0	1
1	1
2	2
3	2
4	1
5	1
6	2
7	6
8	6
9	6
10	2
11	1
12	1
13	4
14	13
15	27
16	39
17	39
18	27
19	13
20	4
21	1
22	1
23	4
24	22
25	60
26	139
27	208
28	252
29	208
30	139
31	60
32	22
33	4
34	1
35	1
36	6
37	34
38	129
39	371
40	794
41	1310
42	1675
43	1675
44	1310
45	794
46	371
47	129
48	34
49	6
50	1
51	1
52	6
53	48
54	218
55	813
56	2196
57	4767
58	8070
59	11139
60	12300
61	11139
62	8070
63	4767
64	2196
65	813
66	218
67	48
68	6
69	1

[1, 1, 2, 2, 1, 1, 2, 6, 6, 6, 2, 1, 1, 4, 13, 27, 39, 39, 27, 13, 4, 1, 1, 4, 22, 60, 139, 208, 252, 208, 139, 60, 22, 4, 1, 1, 6, 34, 129, 371, 794, 1310, 1675, 1675, 1310, 794, 371, 129, 34, 6, 1, 1, 6, 48, 218, 813, 2196, 4767, 8070, 11139, 12300, 11139, 8070, 4767, 2196, 813, 218, 48, 6, 1]

cp's OEIS Frontend

A226290 Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (3,n)-rectangular grid with k '1's and (3n-k) '0's: two patterns are in same class if one of them can be obtained by a reflection or 180-degree rotation of the other.

Table of values

List of values