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Research draft

abundant number

vr.tr.abundant-number · XCT.QTY

Let an agent handle abundant numbers by definition, examples, related classes and open problems.

Thing Registry Cross-cutting context

Research draft, second pass

A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.

written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify

Researched by: Claude

Purpose and description

Let an agent handle abundant numbers by definition, examples, related classes and open problems.

A positive integer for which the sum of its proper divisors exceeds the number itself, such as 12 (1 + 2 + 3 + 4 + 6 = 16); related classes include primitive abundant, weird and quasiperfect numbers.

What it is for: Number theory and classification of integers.

It can be test whether a number is abundant; list abundant numbers; relate them to perfect and deficient numbers; describe related open problems.

Distinguishing features

Divisor sum exceeds the number

Infinitely many

Most are even

Related to weird numbers

What it looks like

Integers such as 12, 18, 20, 24 and 30.

How it is recognised

Sum of proper divisors greater than the number

Smallest odd abundant number is 945

Perfect numbers have equal sums

Related models

is a kind of - category

positive integer

is contrasted with - classes

perfect number and deficient number

is defined by - concept

divisor

is studied in - field

number theory

In practice

Families and kinds

primitive abundant numbers

odd abundant numbers

weird numbers

quasiperfect numbers (hypothetical)

Identifiers

OEIS A005101 integer sequence

Failure modes and hazards

Counting the number itself among proper divisors

Stating open problems as solved

Also called

admirable numberprimitive abundant numberweird numberquasiperfect number

Where this came from

wikidata · CC0 1.0

Drafted structure

Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.

Test Is it abundant.

Divisor sums decide.

Check

Sum of divisors.

Check

Abundance test.

  1. Is this number abundant, perfect or deficient? boundary
  2. What is its abundance? measurement

Primitive

No abundant divisors.

Primitive

Primitive abundance.

  1. Is it primitive abundant? boundary
  2. Which divisors are abundant? definition
Examples Known values.

Examples illustrate.

List

Sequence.

List

List of abundant numbers.

  1. What are the first abundant numbers? provenance
  2. Which is the smallest odd one? definition

Weird

Weird numbers.

Weird

Weird numbers.

  1. What makes a number weird? definition
  2. Is 70 the smallest? provenance
Theory Results.

Theory gives structure.

Density

How common.

Density

Density.

  1. What proportion of integers are abundant? measurement
  2. Which source gives the estimate? provenance

Open

Unsolved.

Open

Open problems.

  1. Are odd weird numbers or quasiperfect numbers known to exist? provenance
  2. Is the status stated accurately? boundary
Learning Teaching.

Activities engage learners.

Activities

Exercises.

Activities

Activities.

  1. Which exercises help learners classify numbers by divisor sums? action
  2. How can divisors be found quickly? action

History

Origins.

History

History.

  1. How were abundant numbers classified historically? provenance
  2. Which mathematicians studied them? provenance

What the second pass must settle

  • Should weird numbers be a separate entry?
  • How should OEIS data be linked?
  • How should quasiperfect numbers be described?