SelfEvacuatingTableauCount
The standard Young tableaux of the shape that evacuation fixes, equivalently its standard domino tableaux.
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St000618via IntegerPartition✓SelfEvacuatingTableauCount(partition)The standard Young tableaux of the shape that evacuation fixes, equivalently its standard domino tableaux.Typed signatures
| Type | Package | Applies |
|---|---|---|
(integer_partition) -> number | combinatorics | always |
Details
- Defined over
IntegerPartitionas an expression in_x, evaluated by compute-engine — the definition IS the implementation. - Takes a
IntegerPartitionand nothing else — it reads values against their positions, or walks the orbits, so it needs the bijection. Applying it to a bare list is a type error, not a wrong answer.
Definition
Epsil, as the implementation runs it.
on IntegerPartition, over _x
0 if Length(_x) < 1 else Apply(
(t: list<integer>) => (1 if (Sum(_x) - Sum(_x) %
2) / 2 ==
0 else Product(Range(
1,
(Sum(_x) -
Sum(_x) % 2) /
2,
))) *
Product(Map(
Function(Product(Map(
Function((t[j] - t[i]) /
2 if j < i &&
(t[j] - t[i]) %
2 ==
0 else 1, j),
Range(1, Length(t)),
)), i),
Range(
1,
Length(t),
),
)) /
Product(Map(Function(
1 if (j -
j % 2) /
2 ==
0 else Product(Range(1, (j -
j % 2) /
2)),
j,
), t)) if Sum(Map(Function((j -
j %
2) /
2, j), t)) -
(Count(Filter(
t,
Function(j % 2 ==
0, j),
)) * (Count(Filter(t, Function(j % 2 ==
0, j))) -
1) /
2 + Count(Filter(
t,
Function(j % 2 ==
1, j),
)) * (Count(Filter(t, Function(j % 2 ==
1, j))) -
1) /
2) == (Sum(_x) - Sum(_x) %
2) / 2 else 0,
Map(
Function(_x[i] + (Length(_x) - i), i),
Range(1, Length(_x)),
),
)Examples
Properties #
About
| Examples | 5 |
|---|---|
| Crosswalk | FindStat |