W-0015
A superpermutation on 8 symbols, found by Uku Raudvere. It beat the previous record, W-0011, by 1 letter, and was the record for n = 8 from Jul 26 until Sep 28, 2026, when W-0022 was 14 letters shorter.
- Length
- 46,204
- Repeated occurrences
- 0
- Announced
- Jul 26, 2026
012345670123456071234560172345601273456012374560123475601234576012345067123450617234506127345061237450612347506123457061…
Windows
| 46,197 | windows of 8 consecutive letters | |
| = | 40,320 | distinct permutations, all 8! of them |
| + | 0 | repeated occurrences of a permutation |
| + | 5,877 | windows that are not permutations |
How it was found
Robin Houston described it as a tree-like superpermutation with a standard kernel and 833 2-cycle extensions; the first n = 8 word shorter than Egan's.
Checking
| Program | Source | Result | Time |
|---|---|---|---|
| permcheck | c46d3654 | all 40,320 permutations appear | under 1 s |
| literal_check | f4687121 | agrees on coverage | under 1 s |
Download
Download Detour (.detour) 420 bytes, or 46.2 kB decoded
Download text (.txt) 46.2 kB
# check it yourself
detour decode W-0015.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 8 ../W-0015.detour 46204
./target/release/bitmapcheck 8 ../W-0015.detour 46204
./target/release/wordhash 8 ../W-0015.detour 46204
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 = 8 and sync exponent 0. The file has 5,843 tokens: 1 START, 1 literal of 1 byte in all, and 5,841 deviations. Deviations by weight, from 1 to 8: 0 · 5,838 · 3 · 0 · 0 · 0 · 0 · 0.