A377066 Number of 4 X n 0..2 matrices with row sums n and column sums 4 up to permutations of rows.

1, 1, 3, 12, 117, 1421, 20326, 307063, 4809897, 77098437, 1257981093, 20817768368, 348552520988, 5893520355308, 100492937876761, 1726068011602392, 29836176505279377, 518637160845827153, 9060385447950862705, 158987518980922356784, 2801031979220628009327

Offset: 0

Author

Andrew Howroyd, Oct 15 2024

Keywords

• nonn

Comments

Also, the number of 4 X n {-1,0,1} matrices with all rows and columns summing to zero up to permutations of rows.

Examples

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

Crossrefs

Row n=4 of A377063.

Cf. A172642, A377065, A377068.