Como usar (3 passos)
- Select Text (anagrams) or Counts (symbol + count).
- Choose Exact or Approx. Exact shows the full integer when safe.
- Copy a shareable URL to reproduce the same state.
Resultados
Exact value (Exact mode): —
Digits: —
Scientific notation: —
Breakdown (counts)
—
| Symbol | Count |
|---|
Random examples (small n)
Generates distinct permutations uniformly when n ≤ 30. Use a seed for reproducibility.
FAQ
What is a multiset permutation (anagram count)?
It counts distinct arrangements when some items are identical, e.g., the number of unique anagrams of BANANA.
What is the formula?
If total items are n and repeated counts are n1..nk, then Count = n! / (n1! n2! … nk!).
What is the difference from “permutations with repetition” (n^r)?
Multiset permutations mean the duplicates are already present (BANANA). n^r means you can reuse items while choosing (PIN codes).
Why is the result 1 when n = 0?
There is exactly one way to arrange zero items: do nothing (the empty permutation).
What if Exact is rejected?
Switch to Approx to see a reliable digit count and scientific notation without building the huge integer.
How can I compute this in Excel?
Use factorials: =FACT(n)/PRODUCT(FACT(n1),FACT(n2),...). For large n, Excel may overflow; use Approx here instead.
How it’s calculated
- Text mode counts characters after normalization and optional filtering, then applies
n! / ∏(ni!). - Exact uses a BigInt-safe product of binomial coefficients:
Count = C(n,n1)·C(n−n1,n2)·…. - Approx uses log-factorials to compute digit count and scientific notation without building the huge integer.