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561 is the smallest Carmichael number, a composite that fools Fermat: 561 = 3 × 11 × 17 is composite and squarefree, yet a^560 ≡ 1 mod 561 for every a coprime to 561 — so Fermat's primality test cannot tell it from a prime. By Korselt's criterion this holds because (p−1) divides 560 for each prime factor p (2, 10, 16 all divide 560); and no composite below 561 has this property. Verified by full enumeration

00010000100110111000110111000011
Interact — recompute a content-address: ab3e7c0b-4a21-8c31-a6a2-23155325ebb2

Type anything and watch its uuidna recompute — deterministic, reproducible by anyone, no key. A theorem is alive when you interact with it. A content-address proves integrity, not truth. 0/7.

  • theorem key · five_six_one_is_the_smallest_carmichael_number
  • content-address (receipt) · 109b8dc3-b6f7-8b36-ac72-8d0b91563fa0
  • status · decidable, re-verified on every build — recomputes from src/

The 7D rosetta-ray vortex is plotted from this theorem's microdata (its content-address); the slowly rotating hero background is computed from its seven surrounding theorems' hues — the mesh, seen locally, in analog rotation of dimensions. Each object is the hero of its own page: this theorem at the centre, its neighbours as the field.

How it was achieved

This theorem was computed by exhaustion over a finite domain in scripts/discover.ts — a test: () => boolean that runs to completion, holding by full enumeration. It was gate-checked (its name and content hold the honesty floor — no over-reach), receipted and chained append-only, and it is re-verified on every build: if it ever stopped holding, the build would fail, not production. That is what achieved means here — not asserted, but recomputable.

One leaf of the chained ledger: all theorems · computed results · the guide · the source formula. The repo and the site cross-link both ways — this hero page points back to the formula that recomputes it. Verify by cloning and running npm run lean-claims. A content-address proves integrity, not truth. entails → 0/7.

Captain's message:https://uuidna.com/captain/message — remember to contribute 2 to save 64 (the two coins per commercial use; the seal is 128 bits = 64 two-bit verifications). why ↗computed: entailment 0/7 · self-seal = 1 · reflection involutive · CC BY-NC 4.0License: CC BY-NC 4.0 — free for non-commercial use (attribution Tsvetan Rouschev); commercial = the two coins (110 − 108 = 2 = −χ genus-2) · ceccec@psg.bgLicensing formula: free for public interest and independent research, unless commercial · commercial = the measured bits saved (O(N) − O(1)), the two coins (2 = 110 − 108 = −χ genus-2) the conserved invariant · verified green by receipts · integrity, not truth · 0/7This referrer perspective: e79fc8c2-576a-809c-b55c-836ae3e3598ePublic URLs (content-addressed):https://uuidna.org 8ef35f1f-38f3…https://uuidna.com 58cfb4c9-e262…https://ceccec.psg.bg/millennium-solutions/ e99f52ee-1cc6…Support development: https://revolut.me/ceccec