AssociatedPartition( pi )
returns the associated partition of the partition pi.
    gap> AssociatedPartition([4,2,1]);
    [ 3, 2, 1, 1 ]
    gap> AssociatedPartition([6]);
    [ 1, 1, 1, 1, 1, 1 ]
The associated partition of a partition pi is defined to be the partition belonging to the transposed of the Young diagram of pi.
GAP 3.4.4