W-0068

A superpermutation on 13 symbols, found by Jakub Halfar. It beat the previous record, W-0067, by 169 letters, and was the record for n = 13 from Oct 8 until Oct 20, 2026, when W-0075 was 74 letters shorter.

Length: 6,747,802,393
Repeated occurrences: 1,797,600
Announced: Oct 8, 2026

Begins

0123456789ABC0123456789AB0C123456789AB01C23456789AB012C3456789AB0123C456789AB01234C56789AB012345C6789AB0123456C789AB0123…

Windows

	6,747,802,381	windows of 13 consecutive letters
=	6,227,020,800	distinct permutations, all 13! of them
+	1,797,600	repeated occurrences of a permutation
+	518,983,981	windows that are not permutations

How it was found

Halfar's selection N with the order of the runs chosen by integer programmes; 115,673 below Pantone's 6,747,918,066.

Checking

Total check time: 1 min 45 s, including preparation but not time in the queue.

Program	Source	Result	Time
classcheck	41928cce	all 6,227,020,800 permutations appear, by rotation class	40 s
bitmapcheck	288b3f67	agrees, by Lehmer rank	30 s
wordhash	94925fe4	the SHA-256 of the word and of its mirror	35 s

SHA-256d16436fb8d72d0c0e01f4f84ed89aa606bc4410608a6824a42eecc5eb8768853 Compilerrustc 1.89.0 (29483883e 2025-08-04)

Download

Download Detour (.detour) 403.0 kB, or 6.7 GB decoded

Decode to text

# check it yourself
detour decode W-0068.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 13 ../W-0068.detour 6747802393
./target/release/bitmapcheck 13 ../W-0068.detour 6747802393
./target/release/wordhash 13 ../W-0068.detour 6747802393

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 = 13 and sync exponent 0. The file has 57,699,738 tokens: 1 START, 1 literal of 1 byte in all, and 57,699,736 deviations. Deviations by weight, from 1 to 13: 1,797,600 · 16,137,171 · 39,757,662 · 1,342 · 1,394 · 1,257 · 454 · 1,409 · 542 · 688 · 95 · 122 · 0.