Generate Deficient Number Sequence

Use this tool to generate a list of deficient numbers integers where the sum of proper divisors (excluding the number itself) is less than the number. For example, 8 qualifies because 1, 2, and 4 only add up to 7.

The sequence updates live as you type. You can format the display, include index numbers, and copy or export the results with a single click.

Total items: 0
Options
Line-by-line output
Show index numbers

How to Use:

  1. Enter the number of deficient numbers to generate.
  2. Use the toggles to control display:
    • Show one value per line or all in a single line.
    • Display index numbers alongside results.
  3. The output area updates automatically.
  4. Click “Copy Output” to copy the list.
  5. Click “Export to File” to download the sequence.
  6. Use “Clear All” to reset everything.

What Generate Deficient Number Sequence can do:

It checks each number in order, calculates the sum of its proper divisors, and includes it if the sum falls short of the number. You’ll see your list grow as you enter a larger count. Flash feedback confirms each update, and a total counter tracks how many values were generated.

You control the look and format. Want a line-by-line view with index numbers? Done. Need a quick inline copy for code? Also easy.

Example:

Input:

10

Settings: Line-by-line: ON, Show index: OFF

Output:

1
2
3
4
5
7
8
9
10
11

Common Use Cases:

Great for students and teachers studying divisor properties, or for developers testing numeric conditions. Deficient numbers come up in number theory, cryptography, and algorithm design and this tool helps generate them cleanly and quickly with just a few clicks.

Useful Tools & Suggestions:

If you’re focused on numbers that fall short, Generate Perfect Numbers is a great contrast it shows values where the divisors add up exactly to the number. And if you want to test specific cases, Test If a Number Is Deficient helps you check individual values quickly.

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