A333890 - cp's OEIS frontend

A333890 Number of non-isomorphic n X n nonnegative integer symmetric matrices with all row and column sums equal to 5 up to permutations of rows and columns.

n	a(n)
0	1
1	1
2	3
3	13
4	74
5	556
6	5369
7	64000
8	917235
9	15450781
10	300882997
11	6682784998
12	167423745058
13	4687321410460
14	145487540598936
15	4972006889998672
16	185965612590706251
17	7572297055379416985
18	334097417273761302271
19	15905277840810391655517
20	813931037149014145154401

[1, 1, 3, 13, 74, 556, 5369, 64000, 917235, 15450781, 300882997, 6682784998, 167423745058, 4687321410460, 145487540598936, 4972006889998672, 185965612590706251, 7572297055379416985, 334097417273761302271, 15905277840810391655517, 813931037149014145154401]

cp's OEIS Frontend

A333890 Number of non-isomorphic n X n nonnegative integer symmetric matrices with all row and column sums equal to 5 up to permutations of rows and columns.

Table of values

List of values