The Order-Ideal of P{10,11} Corresponding to the (10,11)-Core partition into Odd Parts [17,17,9,9,9,5,3,3,3,3,3,1,1,1,1,1,1,1,1,1]
The occupied vertices of the lattice are indicated by red crosses, and the unoccupied vertices are indicated by black squares. Note that reading the occupied labels along the diagonals from bottom to top, in order, the parities of the labels alternate, and the partition is obtained from the order-ideal by sorting the labels and subtracting [19,18,17, ..., 0]
(In general, if the number of parts of the partition is k, you subtract from the sorted list of the labels of the order ideal the vector [k-1, ..., 0] )