Double Factorial of n: 3 Integer n

Specific conversion page with reference context, calculator, and nearby values.

Author

Dr. Amara Osei

Math editorial contributor

Ghanaian computational linguist with a PhD from MIT, specializing in NLP for low-resource African languages

Reviewed by

Prof. Hans Muller

Math content reviewer

German renewable energy engineer at TU Munich, pioneering grid-scale hydrogen storage solutions

Last updatedFebruary 22, 2026

PublishedFebruary 22, 2026

Table of Contents

  1. Value details
  2. Calculator
  3. Nearby reference values
  4. FAQs
  5. Methodology and review
  6. Navigation and related conversions

3 Integer n converts to

3 Double Factorial Value

Use this as a quick reference for Double Factorial of n.

Value Details

Input: 3 Integer n

Output: 3 Double Factorial Value

Browse all reference values for Double Factorial of n

Double Factorial of n

Calculate n!! for non-negative integers up to 21 using the alternating-step factorial product.

Calculated Result

Nearby Reference Values

Double Factorial of n values near 3 Integer n
nn!!
0 Integer n1 Double Factorial Value
1 Integer n1 Double Factorial Value
2 Integer n2 Double Factorial Value
3 Integer n3 Double Factorial Value
4 Integer n8 Double Factorial Value
5 Integer n15 Double Factorial Value
6 Integer n48 Double Factorial Value
7 Integer n105 Double Factorial Value
8 Integer n384 Double Factorial Value
9 Integer n945 Double Factorial Value
10 Integer n3,840 Double Factorial Value
11 Integer n10,395 Double Factorial Value
12 Integer n46,080 Double Factorial Value
13 Integer n135,135 Double Factorial Value

Frequently Asked Questions

Common questions about Double Factorial of n, formulas, and expected usage.

What does the Double Factorial of n calculator do?

It helps with working with combinatorics identities, integrals, and closed-form sequences.

What formula does the Double Factorial of n calculator use?

n!! multiplies every other integer from n down to 1 or 2.

What inputs are valid?

n must be an integer from 0 to 21 for exact safe integer results in this calculator.

When would I use this?

working with combinatorics identities, integrals, and closed-form sequences

Methodology and Review

This page is generated from the same conversion definition used by the main calculator page, which keeps the calculator, reference table rows, and FAQ schema aligned.

Reviewer and update metadata are shown above and included in structured data. See our editorial policy, review process, and corrections policy.

Use this page as a fast lookup reference, then confirm final project values using applicable standards and manufacturer documentation.