Superpermutation Almanac

n = 12

W-0046

A superpermutation on 12 symbols, found by Jakub Halfar. It beat the previous record, W-0035, by 43 letters, and was the record for n = 12 on Oct 4, 2026, when W-0049 was 7 letters shorter.

Length
522,745,538
Repeated occurrences
169,343
Announced
Oct 4, 2026
Begins 0123456789AB0123456789A0B123456789A021B3456789A0213B456789A02134B56789A021345B6789A0213456B789A02134567B89A021345678B9A0…

Windows

522,745,527windows of 12 consecutive letters
=479,001,600distinct permutations, all 12! of them
+169,343repeated occurrences of a permutation
+43,574,584windows that are not permutations

How it was found

Same pieces as Pantone's word, with different cuts and order (PR #5).

Checking

Total check time: 9 s, including preparation but not time in the queue.

ProgramSourceResultTime
classcheck41928cceall 479,001,600 permutations appear, by rotation class3 s
bitmapcheck288b3f67agrees, by Lehmer rank2 s
wordhash94925fe4the SHA-256 of the word and of its mirror3 s
SHA-256dd978ce87e586e8bda8b6b6aedf0c10977d657182720757afa64143f23266499 Compilerrustc 1.89.0 (29483883e 2025-08-04)

Download

Download Detour (.detour) 40.7 kB, or 522.7 MB decoded

Decode to text

# check it yourself
detour decode W-0046.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 12 ../W-0046.detour 522745538
./target/release/bitmapcheck 12 ../W-0046.detour 522745538
./target/release/wordhash 12 ../W-0046.detour 522745538

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 = 12 and sync exponent 0. The file has 4,904,474 tokens: 1 START, 1 literal of 1 byte in all, and 4,904,472 deviations. Deviations by weight, from 1 to 12: 169,343 · 1,354,703 · 3,380,050 · 87 · 79 · 101 · 31 · 15 · 39 · 13 · 8 · 3.