W-0073
A superpermutation on 8 symbols, found by William Echols. It beat the previous record, W-0028, by 3 letters, and was the record for n = 8 from Oct 19 until Oct 20, 2026, when W-0077 was 4 letters shorter.
- Length
- 46,178
- Repeated occurrences
- 86
- Announced
- Oct 19, 2026
012345670123456071234560172345601273456012374560123547601235467012354607123546017235460127354601237546012357460123564701…
Windows
| 46,171 | windows of 8 consecutive letters | |
| = | 40,320 | distinct permutations, all 8! of them |
| + | 86 | repeated occurrences of a permutation |
| + | 5,765 | windows that are not permutations |
How it was found
Found with GPT-6.1 Sol in Codex. A new selection in Pantone's completion, with rows of any visible length as Halfar developed them; it has charge 92 and two closed trails. 3 shorter than Pantone's 46,181.
Checking
Total check time: under 1 s, including preparation but not time in the queue.
| Program | Source | Result | Time |
|---|---|---|---|
| classcheck | 41928cce | all 40,320 permutations appear, by rotation class | under 1 s |
| bitmapcheck | 288b3f67 | agrees, by Lehmer rank | under 1 s |
| wordhash | 94925fe4 | the SHA-256 of the word and of its mirror | under 1 s |
Download
Download Detour (.detour) 380 bytes, or 46.2 kB decoded
Download text (.txt) 46.2 kB
# check it yourself
detour decode W-0073.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-0073.detour 46178
./target/release/bitmapcheck 8 ../W-0073.detour 46178
./target/release/wordhash 8 ../W-0073.detour 46178
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 1,137 tokens: 1 START, 1 literal of 1 byte in all, and 1,135 deviations. Deviations by weight, from 1 to 8: 86 · 332 · 717 · 0 · 0 · 0 · 0 · 0.