A080858 - cp's OEIS frontend

A080858 Triangle read by rows: T(n,k), n >=1, 0 <= k <= C(n,k), = number of n X n symmetric positive definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with k 1's above the diagonal.

n	a(n)
1	1
2	1
3	1
4	1
5	3
6	3
7	1
8	1
9	6
10	15
11	20
12	12
13	6
14	1
15	1
16	10
17	45
18	120
19	190
20	192
21	140
22	80
23	30
24	10
25	1
26	1
27	15
28	105
29	455
30	1290
31	2382
32	3385
33	3195
34	2880
35	1860
36	1098
37	435
38	240
39	60
40	15
41	1
42	1
43	21
44	210
45	1330
46	5775
47	17157
48	36092
49	60210
50	75075
51	87185
52	68775
53	64470
54	38395
55	26355
56	13125
57	7987
58	2394
59	1365
60	560
61	105
62	21
63	1
64	1
65	28
66	378
67	3276
68	19985
69	86772
70	265286
71	595136
72	1104642
73	1499680
74	2036412
75	2057496
76	2115855
77	1729672
78	1508580
79	912128
80	755300
81	378336
82	260848
83	120120
84	80388
85	26384
86	16856
87	4200
88	3640
89	840
90	168
91	28
92	1

[1, 1, 1, 1, 3, 3, 1, 1, 6, 15, 20, 12, 6, 1, 1, 10, 45, 120, 190, 192, 140, 80, 30, 10, 1, 1, 15, 105, 455, 1290, 2382, 3385, 3195, 2880, 1860, 1098, 435, 240, 60, 15, 1, 1, 21, 210, 1330, 5775, 17157, 36092, 60210, 75075, 87185, 68775, 64470, 38395, 26355, 13125, 7987, 2394, 1365, 560, 105, 21, 1, 1, 28, 378, 3276, 19985, 86772, 265286, 595136, 1104642, 1499680, 2036412, 2057496, 2115855, 1729672, 1508580, 912128, 755300, 378336, 260848, 120120, 80388, 26384, 16856, 4200, 3640, 840, 168, 28, 1]

cp's OEIS Frontend

A080858 Triangle read by rows: T(n,k), n >=1, 0 <= k <= C(n,k), = number of n X n symmetric positive definite matrices with 2's on the main diagonal and 1's and 0's elsewhere and with k 1's above the diagonal.

Table of values

List of values