A277080 - cp's OEIS frontend

A277080 Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged by reverse.

n	a(n)
0	1
1	1
2	1
3	1
4	1
5	0
6	1
7	1
8	0
9	3
10	0
11	3
12	0
13	1
14	1
15	0
16	12
17	0
18	66
19	0
20	220
21	0
22	495
23	0
24	792
25	0
26	924
27	0
28	792
29	0
30	495
31	0
32	220
33	0
34	66
35	0
36	12
37	0
38	1
39	1
40	0
41	60
42	0
43	1770
44	0
45	34220
46	0
47	487635
48	0
49	5461512
50	0
51	50063860
52	0
53	386206920
54	0
55	2558620845
56	0
57	14783142660
58	0
59	75394027566

[1, 1, 1, 1, 1, 0, 1, 1, 0, 3, 0, 3, 0, 1, 1, 0, 12, 0, 66, 0, 220, 0, 495, 0, 792, 0, 924, 0, 792, 0, 495, 0, 220, 0, 66, 0, 12, 0, 1, 1, 0, 60, 0, 1770, 0, 34220, 0, 487635, 0, 5461512, 0, 50063860, 0, 386206920, 0, 2558620845, 0, 14783142660, 0, 75394027566]

cp's OEIS Frontend

A277080 Irregular triangle read by rows: T(n,k) = number of size k subsets of S_n that remain unchanged by reverse.

Table of values

List of values