A228168 - cp's OEIS frontend

A228168 Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (9,n)-rectangular grid with k '1's and (9n-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	5
3	20
4	44
5	66
6	66
7	44
8	20
9	5
10	1
11	1
12	5
13	45
14	208
15	792
16	2156
17	4704
18	7984
19	11034
20	12190
21	11034
22	7984
23	4704
24	2156
25	792
26	208
27	45
28	5
29	1
30	1
31	10
32	106
33	785
34	4554
35	20556
36	74828
37	223498
38	557599
39	1175574
40	2114550
41	3266415
42	4354188
43	5023464
44	5023464
45	4354188

[1, 1, 5, 20, 44, 66, 66, 44, 20, 5, 1, 1, 5, 45, 208, 792, 2156, 4704, 7984, 11034, 12190, 11034, 7984, 4704, 2156, 792, 208, 45, 5, 1, 1, 10, 106, 785, 4554, 20556, 74828, 223498, 557599, 1175574, 2114550, 3266415, 4354188, 5023464, 5023464, 4354188]

cp's OEIS Frontend

A228168 Irregular triangle read by rows: T(n,k) is the number of binary pattern classes in the (9,n)-rectangular grid with k '1's and (9n-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