T(n,k) is the number of lower triangles of an n X n 0..k array with all row sums equal to the length of the row and all column sums equal to the length of the column.

A195644

T(n,k) is the number of lower triangles of an n X n 0..k 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) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =3a(9) =1a(10) =1a(11) =1a(12) =3a(13) =15a(14) =1a(15) =1a(16) =1a(17) =3a(18) =19a(19) =199a(20) =1a(21) =1a(22) =1a(23) =3a(24) =19a(25) =379a(26) =6247a(27) =1a(28) =1a(29) =1

External references