W-0018
A superpermutation on 11 symbols, found by Uku Raudvere. It was the first record for n = 11, and held it from Jul 27 until Sep 29, 2026, when W-0025 was 18,118 letters shorter.
- Length
- 43,948,807
- Repeated occurrences
- 0
- Announced
- Jul 27, 2026
0123456789A01234567890A12345678901A23456789012A34567890123A45678901234A56789012345A67890123456A78901234567A89012345678A9…
Windows
| 43,948,797 | windows of 11 consecutive letters | |
| = | 39,916,800 | distinct permutations, all 11! of them |
| + | 0 | repeated occurrences of a permutation |
| + | 4,031,997 | windows that are not permutations |
How it was found
Lifted from Echols's n = 10 certificate by Raudvere's recursive complete-2-cycle constructor (Egan's length minus 1).
Checking
| Program | Source | Result | Time |
|---|---|---|---|
| permcheck | c46d3654 | all 39,916,800 permutations appear | 2 s |
| literal_check | f4687121 | agrees on coverage | 3 s |
Download
Download Detour (.detour) 4.5 kB, or 43.9 MB decoded
# check it yourself
detour decode W-0018.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 11 ../W-0018.detour 43948807
./target/release/bitmapcheck 11 ../W-0018.detour 43948807
./target/release/wordhash 11 ../W-0018.detour 43948807
Decoding needs detour; see the Detour format for how to build and install it. The checkers are in checkers-rs-source.tar.gz, which needs Rust 1.89 or later; each one decodes the file itself, so the word is never written out.
The file's header gives n = 11 and sync exponent 0. The file has 4,031,921 tokens: 1 START, 1 literal of 1 byte in all, and 4,031,919 deviations. Deviations by weight, from 1 to 11: 0 · 4,031,913 · 6 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0.