W-0040

A superpermutation on 10 symbols, found by rumstd. It beat the previous record, W-0033, by 16 letters, and was the record for n = 10 from Oct 2 until Oct 6, 2026, when W-0062 was 18 letters shorter.

Length: 4,034,873
Repeated occurrences: 2,351
Announced: Oct 2, 2026

Begins

012345678901234567809123456780192345678012934567801239456780123495678012345967801234569780123456798012345670891234567081…

Windows

	4,034,864	windows of 10 consecutive letters
=	3,628,800	distinct permutations, all 10! of them
+	2,351	repeated occurrences of a permutation
+	403,713	windows that are not permutations

How it was found

PR #3 ('based on your n=10 word of length 4034889'); Halfar credits this word with the trick of cutting a closed trail between two 2-cycles so that pieces chain with no join cost.

Checking

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

Program	Source	Result	Time
classcheck	41928cce	all 3,628,800 permutations appear, by rotation class	under 1 s
bitmapcheck	288b3f67	agrees, by Lehmer rank	under 1 s
wordhash	94925fe4	the SHA-256 of the word and of its mirror	under 1 s

SHA-2566f50f2c5460e928c68a6250c7dae73e72ab254aa46d2f752cf63aae4d8bdc6ca Compilerrustc 1.89.0 (29483883e 2025-08-04)

Download

Download Detour (.detour) 1.9 kB, or 4.0 MB decoded

Decode to text

# check it yourself
detour decode W-0040.detour - | tr -d '\n' | shasum -a 256
tar xzf checkers-rs-source.tar.gz && cd checkers-rs && cargo build --release --locked
./target/release/classcheck 10 ../W-0040.detour 4034873
./target/release/bitmapcheck 10 ../W-0040.detour 4034873
./target/release/wordhash 10 ../W-0040.detour 4034873

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 = 10 and sync exponent 0. The file has 54,037 tokens: 1 START, 1 literal of 1 byte in all, and 54,035 deviations. Deviations by weight, from 1 to 10: 2,351 · 14,105 · 37,513 · 15 · 5 · 6 · 39 · 1 · 0 · 0.