A333734 Number of non-isomorphic n X n nonnegative integer matrices with all row and column sums equal to n up to permutations of rows and columns.

1, 1, 2, 5, 43, 1856, 1217727, 8597641912, 646296747486387, 535435113671568180963, 5081029530811947425598907884, 570680215340337514993573217774604779, 779646755088025699677478853259568262608053838

Offset: 0

Author

Andrew Howroyd, Apr 04 2020

Keywords

• nonn
• more

Examples

			The a(2) = 2 matrices are:
  [1 1]  [2 0]
  [1 1]  [0 2]
.
The a(3) = 5 matrices are:
  [1 1 1]   [2 1 0]   [2 1 0]   [3 0 0]   [3 0 0]
  [1 1 1]   [1 1 1]   [0 2 1]   [0 2 1]   [0 3 0]
  [1 1 1]   [0 1 2]   [1 0 2]   [0 1 2]   [0 0 3]
		

Crossrefs

Main diagonal of A333733 and A377060.

Cf. A110058.

Extensions

a(11)-a(12) from Andrew Howroyd, Oct 14 2024