BoxedOccurrencesOf132
Occurrences of 132 with no other entry positioned between the first and last and valued between the least and greatest.
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St001083via Permutation✓BoxedOccurrencesOf132(p)Occurrences of 132 with no other entry positioned between the first and last and valued between the least and greatest.Typed signatures
| Type | Package | Applies |
|---|---|---|
(list<integer> | permutation) -> number | combinatorics | always |
Details
- Defined over
Permutationas an expression in_x, evaluated by compute-engine — the definition IS the implementation. - Takes a
Permutation, and also a bare list of integers: this reading compares entries with each other rather than with their positions, so it stands on any sequence.
Definition
Epsil, as the implementation runs it.
on Permutation, over _x
0 if Length(_x) < 3 else Sum(Map(Function(Sum(Map(
Function(Count(Filter(
Range(
j + 1,
Length(_x),
),
Function(_x[i] < _x[k] &&
_x[k] < _x[j] &&
Count(Filter(
Range(1, Length(_x)),
Function(m > i &&
m < k &&
m != j &&
_x[m] > _x[i] &&
_x[m] < _x[j], m),
)) ==
0, k),
)), j),
Range(i + 1, Length(_x)),
)), i), Range(1, Length(_x))))Examples
Basic #
Properties #
About
| Examples | 6 |
|---|---|
| Crosswalk | FindStat |