W-0031

A superpermutation on 13 symbols, found by Jay Pantone jaypantone. It beat the previous record, W-0027, by 19,328 letters, and was the record for n = 13 from Sep 29 until Oct 1, 2026, when W-0036 was 49,732 letters shorter.

Length: 6,747,967,798
Repeated occurrences: 1,693,440
Announced: Sep 29, 2026

Begins

0123456789ABC0123456789AB0C123456789AB01C23456789AB012C3456789AB0123C456789AB01234C56789AB012345C6789AB0123456C789AB0123…

Windows

	6,747,967,786	windows of 13 consecutive letters
=	6,227,020,800	distinct permutations, all 13! of them
+	1,693,440	repeated occurrences of a permutation
+	519,253,546	windows that are not permutations

How it was found

The tighter construction (25,584 connector cycles instead of 25,704).

Checking

Total check time: 2 min 7 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	48 s
bitmapcheck	288b3f67	agrees, by Lehmer rank	39 s
wordhash	94925fe4	the SHA-256 of the word and of its mirror	39 s

SHA-25646aed6b5b16efcd226e23203e4d5304b72bf88b20c5840bd78609f6de48b3634 Compilerrustc 1.89.0 (29483883e 2025-08-04)

Download

Download Detour (.detour) 203.7 kB, or 6.7 GB decoded

Decode to text

# check it yourself
detour decode W-0031.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-0031.detour 6747967798
./target/release/bitmapcheck 13 ../W-0031.detour 6747967798
./target/release/wordhash 13 ../W-0031.detour 6747967798

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 54,109,936 tokens: 1 START, 1 literal of 1 byte in all, and 54,109,934 deviations. Deviations by weight, from 1 to 13: 1,693,440 · 15,240,960 · 37,163,884 · 64 · 13 · 2,122 · 2,397 · 774 · 100 · 170 · 325 · 452 · 5,233.