Array read by antidiagonals: number of antichains (or order ideals) in the poset 3*m*n or plane partitions with rows <= m, columns <= n and entries <= 3.
A056939
Array read by antidiagonals: number of antichains (or order ideals) in the poset 3*m*n or plane partitions with rows <= m, columns <= n and entries <= 3.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =4a(5) =1a(6) =1a(7) =10a(8) =10a(9) =1a(10) =1a(11) =20a(12) =50a(13) =20a(14) =1a(15) =1a(16) =35a(17) =175a(18) =175a(19) =35a(20) =1a(21) =1a(22) =56a(23) =490a(24) =980a(25) =490a(26) =56a(27) =1a(28) =1a(29) =84
External references
- oeis: A056939