Number of lower triangles of an n X n 0..3 array with all row sums equal to the length of the row and all column sums equal to the length of the column.
A195639
Number of lower triangles of an n X n 0..3 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) =379a(5) =22506a(6) =4063437a(7) =2303397986
External references
- oeis: A195639