W-0070
A superpermutation on 14 symbols, found by William Echols. It was the first record for n = 14, and held it from Oct 17 until Oct 19, 2026, when W-0072 was 131,516 letters shorter.
- Length
- 93,904,936,032
- Repeated occurrences
- 19,588,800
- Announced
- Oct 17, 2026
0123456789ABCD0123456789ABC0D123456789ABC01D23456789ABC012D3456789ABC0123D456789ABC01234D56789ABC012345D6789ABC0123456D7…
Windows
| 93,904,936,019 | windows of 14 consecutive letters | |
| = | 87,178,291,200 | distinct permutations, all 14! of them |
| + | 19,588,800 | repeated occurrences of a permutation |
| + | 6,707,056,019 | windows that are not permutations |
How it was found
Pantone's construction on Halfar's selection C, lifted twice (Echols's 2-lift recipe, found with GPT-6 Pro). Published only as a recipe (93904936032.spc.xz and decode.py), not as a word.
Checking
Total check time: 26 min 21 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 | 11 min 8 s |
| bitmapcheck | 288b3f67 | agrees, by Lehmer rank | 7 min 29 s |
| wordhash | 94925fe4 | the SHA-256 of the word and of its mirror | 7 min 44 s |
Download
Download Detour (.detour) 1.5 MB, or 93.9 GB decoded
# check it yourself
detour decode W-0070.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-0070.detour 93904936032
./target/release/bitmapcheck 14 ../W-0070.detour 93904936032
./target/release/wordhash 14 ../W-0070.detour 93904936032
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 686,536,116 tokens: 1 START and 686,536,115 deviations, with 327 SYNC tokens besides. Deviations by weight, from 1 to 14: 19,588,800 · 195,888,000 · 471,041,748 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 0 · 17,567.