W-0076
A superpermutation on 14 symbols, found by Jakub Halfar. It beat the previous record, W-0072, by 91 letters, and is the record for n = 14.
- Length
- 93,904,804,425
- Repeated occurrences
- 19,588,800
- Announced
- Oct 20, 2026
0123456789ABCD0123456789ABC0D123456789ABC01D23456789ABC012D3456789ABC0123D456789ABC01234D56789ABC012345D6789ABC0123456D7…
Windows
| 93,904,804,412 | windows of 14 consecutive letters | |
| = | 87,178,291,200 | distinct permutations, all 14! of them |
| + | 19,588,800 | repeated occurrences of a permutation |
| + | 6,706,924,412 | windows that are not permutations |
How it was found
Halfar's selection C with Pantone's construction, lifted twice as in Echols's 2-lift, with the closed trails in the order of Halfar's n = 12 and n = 13 plans on C; 91 below Echols's 93,904,804,516. Published only as a recipe (gen14.c and a unit plan), as Echols published his n = 14 words.
Checking
Total check time: 25 min 11 s, including preparation but not time in the queue.
| Program | Source | Result | Time |
|---|---|---|---|
| classcheck | 41928cce | all 87,178,291,200 permutations appear, by rotation class | 10 min 44 s |
| bitmapcheck | 288b3f67 | agrees, by Lehmer rank | 6 min 52 s |
| wordhash | 94925fe4 | the SHA-256 of the word and of its mirror | 7 min 34 s |
Download
Download Detour (.detour) 3.9 MB, or 93.9 GB decoded
# check it yourself
detour decode W-0076.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 14 ../W-0076.detour 93904804425
./target/release/bitmapcheck 14 ../W-0076.detour 93904804425
./target/release/wordhash 14 ../W-0076.detour 93904804425
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 = 14 and sync exponent 21. The file has 686,531,485 tokens: 1 START and 686,531,484 deviations, with 327 SYNC tokens besides. Deviations by weight, from 1 to 14: 19,588,800 · 195,888,000 · 471,040,414 · 0 · 7,498 · 1,261 · 1,755 · 1,216 · 502 · 779 · 513 · 371 · 203 · 172.