A221879 - cp's OEIS frontend

A221879 Triangle T(n,k) read by rows: Number of order-reversing full contraction mappings (of an n-chain) with 1 fixed point and height exactly k.

n	a(n)
1	1
2	2
3	0
4	3
5	2
6	1
7	4
8	6
9	4
10	0
11	5
12	12
13	12
14	4
15	1
16	6
17	20
18	28
19	18
20	6
21	0
22	7
23	30
24	55
25	52
26	27
27	6
28	1
29	8
30	42
31	96
32	120
33	88
34	36
35	8
36	0
37	9
38	56
39	154
40	240
41	230
42	136
43	48
44	8
45	1
46	10
47	72
48	232
49	434
50	516
51	400
52	200
53	60
54	10
55	0
56	11
57	90
58	333
59	728
60	1036
61	996
62	650
63	280
64	75
65	10
66	1

[1, 2, 0, 3, 2, 1, 4, 6, 4, 0, 5, 12, 12, 4, 1, 6, 20, 28, 18, 6, 0, 7, 30, 55, 52, 27, 6, 1, 8, 42, 96, 120, 88, 36, 8, 0, 9, 56, 154, 240, 230, 136, 48, 8, 1, 10, 72, 232, 434, 516, 400, 200, 60, 10, 0, 11, 90, 333, 728, 1036, 996, 650, 280, 75, 10, 1]

cp's OEIS Frontend

A221879 Triangle T(n,k) read by rows: Number of order-reversing full contraction mappings (of an n-chain) with 1 fixed point and height exactly k.

Table of values

List of values