A377066 - OEIS

%I #7 Oct 15 2024 15:46:59

%S 1,1,3,12,117,1421,20326,307063,4809897,77098437,1257981093,

%T 20817768368,348552520988,5893520355308,100492937876761,

%U 1726068011602392,29836176505279377,518637160845827153,9060385447950862705,158987518980922356784,2801031979220628009327

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

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

%e The a(2) = 3 matrices are:

%e    [1 1]   [2 0]   [2 0]

%e    [1 1]   [1 1]   [2 0]

%e    [1 1]   [1 1]   [0 2]

%e    [1 1]   [0 2]   [0 2]

%Y Row n=4 of A377063.

%Y Cf. A172642, A377065, A377068.

%K nonn

%O 0,3

%A _Andrew Howroyd_, Oct 15 2024