Number of lower triangles of an n X n 0..6 array with all row sums equal to the length of the row and all column sums equal to the length of the column.
A195642
Number of lower triangles of an n X n 0..6 array with all row sums equal to the length of the row and all column sums equal to the length of the column.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =19a(4) =391a(5) =25532a(6) =5539434a(7) =4116036800
External references
- oeis: A195642