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

A333738

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

Terms

    a(0) =1a(1) =1a(2) =2a(3) =5a(4) =33a(5) =556a(6) =31781a(7) =5882230a(8) =3589936407

External references