W-0021
A superpermutation on 7 symbols, found by Andrei Teodorescu. It beat the previous record, W-0014, by 1 letter, and is the record for n = 7.
- Length
- 5,905
- Repeated occurrences
- 0
- Announced
- Aug 17, 2026
012345601234506123450162345012634501243650124356012435061243501624350126435012463501245360124530612453016245301264530124…
Windows
| 5,899 | windows of 7 consecutive letters | |
| = | 5,040 | distinct permutations, all 7! of them |
| + | 0 | repeated occurrences of a permutation |
| + | 859 | windows that are not permutations |
How it was found
Found with Egan's PermutationChains.c on the kernel 4666446666-6666466636666-666646646666-666646646666-6666366646666-6666446664 from KernelFinder.c; four words were posted, two of them distinct up to reversal and relabelling.
Checking
| Program | Source | Result | Time |
|---|---|---|---|
| permcheck | c46d3654 | all 5,040 permutations appear | under 1 s |
| literal_check | f4687121 | agrees on coverage | under 1 s |
Download
Download Detour (.detour) 344 bytes, or 5.9 kB decoded
Download text (.txt) 5.9 kB
# check it yourself
detour decode W-0021.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 7 ../W-0021.detour 5905
./target/release/bitmapcheck 7 ../W-0021.detour 5905
./target/release/wordhash 7 ../W-0021.detour 5905
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 = 7 and sync exponent 0. The file has 443 tokens: 1 START, 1 literal of 1 byte in all, and 441 deviations. Deviations by weight, from 1 to 7: 0 · 398 · 41 · 2 · 0 · 0 · 0.