A178516 - cp's OEIS frontend

A178516 Triangle read by rows: T(n,k) is the number of up-down permutations of {1,2,...,n} having genus k (see first comment for definition of genus).

n	a(n)
1	1
2	1
3	0
4	2
5	0
6	0
7	2
8	3
9	0
10	0
11	6
12	10
13	0
14	0
15	0
16	6
17	38
18	17
19	0
20	0
21	0
22	22
23	142
24	104
25	4
26	0
27	0
28	0
29	22
30	351
31	778
32	234
33	0
34	0
35	0
36	0
37	90
38	1419
39	4086
40	2235
41	106
42	0
43	0
44	0
45	0
46	90
47	2856
48	17402
49	24357
50	5816
51	0
52	0
53	0
54	0
55	0
56	394
57	12208
58	87434
59	171305
60	78705
61	3746
62	0
63	0
64	0
65	0
66	0
67	394
68	21676
69	278062
70	1053425
71	1120648
72	228560
73	0

[1, 1, 0, 2, 0, 0, 2, 3, 0, 0, 6, 10, 0, 0, 0, 6, 38, 17, 0, 0, 0, 22, 142, 104, 4, 0, 0, 0, 22, 351, 778, 234, 0, 0, 0, 0, 90, 1419, 4086, 2235, 106, 0, 0, 0, 0, 90, 2856, 17402, 24357, 5816, 0, 0, 0, 0, 0, 394, 12208, 87434, 171305, 78705, 3746, 0, 0, 0, 0, 0, 394, 21676, 278062, 1053425, 1120648, 228560, 0]

cp's OEIS Frontend

A178516 Triangle read by rows: T(n,k) is the number of up-down permutations of {1,2,...,n} having genus k (see first comment for definition of genus).

Table of values

List of values