W-0012
A superpermutation on 9 symbols, found by Greg Egan. It was the first record for n = 9, and held it from Oct 20, 2018 until Jul 26, 2026, when W-0017 was 1 letter shorter.
- Length
- 408,966
- Repeated occurrences
- 0
- Announced
- Oct 20, 2018
012345678012345670812345607812345608712345608172345608127345608123745608123475608123457608123456701823456071823456017823…
Windows
| 408,958 | windows of 9 consecutive letters | |
| = | 362,880 | distinct permutations, all 9! of them |
| + | 0 | repeated occurrences of a permutation |
| + | 46,078 | windows that are not permutations |
How it was found
Egan's construction at n = 9; his page gives L2(9) = 408,966 and the C program that generates it.
Checking
| Program | Source | Result | Time |
|---|---|---|---|
| permcheck | c46d3654 | all 362,880 permutations appear | under 1 s |
| literal_check | f4687121 | agrees on coverage | under 1 s |
Download
Download Detour (.detour) 320 bytes, or 409.0 kB decoded
Download text (.txt) 409.0 kB
# check it yourself
detour decode W-0012.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 9 ../W-0012.detour 408966
./target/release/bitmapcheck 9 ../W-0012.detour 408966
./target/release/wordhash 9 ../W-0012.detour 408966
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 = 9 and sync exponent 0. The file has 46,074 tokens: 1 START, 1 literal of 1 byte in all, and 46,072 deviations. Deviations by weight, from 1 to 9: 0 · 46,072 · 0 · 0 · 0 · 0 · 0 · 0 · 0.