Square array T(n,k) read by antidiagonals: number of tilings of an <n,k,n> hexagon.

Terms

a(0) =1a(1) =1a(2) =2a(3) =1a(4) =6a(5) =3a(6) =1a(7) =20a(8) =20a(9) =4a(10) =1a(11) =70a(12) =175a(13) =50a(14) =5a(15) =1a(16) =252a(17) =1764a(18) =980a(19) =105a(20) =6a(21) =1a(22) =924a(23) =19404a(24) =24696a(25) =4116a(26) =196a(27) =7a(28) =1a(29) =3432