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ID: past-exam-of-the-lie-algebras-and-representation-theory-of-symmetric-groups-course-of-the-university-of-oxford/2010/b/6

Let be the permutation character of . Young's rule gives , with integer Kostka multiplicities. This dominance-triangular system has diagonal entries one, so recursive subtraction expresses every irreducible character as an integer linear combination of permutation characters. The latter count fixed tabloids, proving that all are integers.
For a -cycle, the Murnaghan–Nakayama rule reduces to
where height is the number of occupied rows minus one, and is the degree of the remaining Specht character at the identity. In particular a full -cycle has character zero unless is a hook, in which case the value is .

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