W-0048
A superpermutation on 11 symbols, found by Jakub Halfar. It beat the previous record, W-0047, by 1 letter, and was the record for n = 11 from Oct 4 until Oct 5, 2026, when W-0052 was 9 letters shorter.
- Length
- 43,930,623
- Repeated occurrences
- 18,815
- Announced
- Oct 4, 2026
0123456789A01234567890A12345678901A23456789012A34567890123A45678901234A56789012345A67890123456A78901234567A89012345678A9…
Windows
| 43,930,613 | windows of 11 consecutive letters | |
| = | 39,916,800 | distinct permutations, all 11! of them |
| + | 18,815 | repeated occurrences of a permutation |
| + | 3,994,998 | windows that are not permutations |
How it was found
One pass of Halfar's fixed-order cut programme on his 43,930,628 (43,930,625), then a further search run; pushed with his 522,745,531.
Checking
Total check time: 1 s, including preparation but not time in the queue.
| Program | Source | Result | Time |
|---|---|---|---|
| classcheck | 41928cce | all 39,916,800 permutations appear, by rotation class | under 1 s |
| bitmapcheck | 288b3f67 | agrees, by Lehmer rank | 1 s |
| wordhash | 94925fe4 | the SHA-256 of the word and of its mirror | under 1 s |
Download
Download Detour (.detour) 7.4 kB, or 43.9 MB decoded
# check it yourself
detour decode W-0048.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-0048.detour 43930623
./target/release/bitmapcheck 11 ../W-0048.detour 43930623
./target/release/wordhash 11 ../W-0048.detour 43930623
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 488,893 tokens: 1 START, 1 literal of 1 byte in all, and 488,891 deviations. Deviations by weight, from 1 to 11: 18,815 · 131,585 · 338,395 · 33 · 14 · 1 · 1 · 39 · 6 · 2 · 0.