A138177 - cp's OEIS frontend

A138177 Triangle T(n,k) read by rows: number of k X k symmetric matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.

n	a(n)
1	1
2	1
3	2
4	1
5	4
6	4
7	1
8	7
9	15
10	10
11	1
12	10
13	36
14	52
15	26
16	1
17	14
18	74
19	176
20	190
21	76
22	1
23	18
24	132
25	460
26	810
27	696
28	232
29	1
30	23
31	222
32	1060
33	2705
34	3756
35	2674
36	764
37	1
38	28
39	347
40	2180
41	7565
42	15106
43	17262
44	10480
45	2620
46	1
47	34
48	525
49	4204
50	19013
51	51162
52	83440
53	80816
54	42732
55	9496
56	1
57	40

[1, 1, 2, 1, 4, 4, 1, 7, 15, 10, 1, 10, 36, 52, 26, 1, 14, 74, 176, 190, 76, 1, 18, 132, 460, 810, 696, 232, 1, 23, 222, 1060, 2705, 3756, 2674, 764, 1, 28, 347, 2180, 7565, 15106, 17262, 10480, 2620, 1, 34, 525, 4204, 19013, 51162, 83440, 80816, 42732, 9496, 1, 40]

cp's OEIS Frontend

A138177 Triangle T(n,k) read by rows: number of k X k symmetric matrices with nonnegative integer entries and without zero rows or columns such that sum of all entries is equal to n, n>=1, 1<=k<=n.

Table of values

List of values