Number of non-isomorphic n X n nonnegative integer matrices with all row and column sums equal to 4 up to permutations of rows and columns.

A232216

Number of non-isomorphic n X n nonnegative integer matrices with all row and column sums equal to 4 up to permutations of rows and columns.

Terms

    a(0) =1a(1) =1a(2) =3a(3) =9a(4) =43a(5) =264a(6) =2804a(7) =44524a(8) =1012456a(9) =30502320a(10) =1166185222a(11) =54902972542

External references