W-0027

A superpermutation on 13 symbols, found by Jay Pantone jaypantone. It beat the previous record, W-0020, by 1,580,883 letters, and was the record for n = 13 on Sep 29, 2026, when W-0031 was 19,328 letters shorter.

Length: 6,747,987,126
Repeated occurrences: 1,693,440
Announced: Sep 29, 2026

Begins

0123456789ABC0123456789AB0C123456789AB01C23456789AB012C3456789AB0123C456789AB01234C56789AB012345C6789AB0123456C789AB0123…

Windows

	6,747,987,114	windows of 13 consecutive letters
=	6,227,020,800	distinct permutations, all 13! of them
+	1,693,440	repeated occurrences of a permutation
+	519,272,874	windows that are not permutations

How it was found

The 43/80 construction at 13 symbols, with cuts and order optimized by computer search; in the repository's first commit.

Checking

Program	Source	Result	Time
permcheck	c46d3654	all 6,227,020,800 permutations appear	8 min 35 s
literal_check	f4687121	agrees on coverage	23 min 38 s

SHA-2566a63c64f2b3e70117b21eeb372787933544dbedb3b37cdb8ef20e209654c45d5 Compilerg++ (Debian 14.2.0-19) 14.2.0

Download

Download Detour (.detour) 243.4 kB, or 6.7 GB decoded

Decode to text

# check it yourself
detour decode W-0027.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-0027.detour 6747987126
./target/release/bitmapcheck 13 ../W-0027.detour 6747987126
./target/release/wordhash 13 ../W-0027.detour 6747987126

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 54,114,999 tokens: 1 START, 1 literal of 1 byte in all, and 54,114,997 deviations. Deviations by weight, from 1 to 13: 1,693,440 · 15,240,960 · 37,162,346 · 264 · 64 · 258 · 1,733 · 3,121 · 4,591 · 5,219 · 2,267 · 656 · 78.