A052372 Number of nonnegative integer 6x6 matrices with sum of elements equal to n, under row and column permutations.

1, 1, 4, 10, 33, 91, 298, 881, 2825, 8791, 27947, 87410, 272991, 837370, 2532012, 7496030, 21735743, 61570427, 170399621, 460413115, 1214983434, 3131870712, 7890604652, 19441462894, 46878788710, 110702854983, 256217556777