Pith Number

pith:O5X4EPIO

pith:2007:O5X4EPIOCHYMPG4HFV65HONLE2

not attested not anchored not stored refs pending

Skew-Hadamard matrices of orders 188 and 388 exist

Dragomir Z. Djokovic

arxiv:0704.0640 v2 · 2007-04-04 · math.CO

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{O5X4EPIOCHYMPG4HFV65HONLE2}

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Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Cited by

1 paper in Pith

A database of constructions of Hadamard matrices

Receipt and verification

First computed	2026-07-04T15:39:33.620516Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

776fc23d0e11f0c79b872d7dd3b9ab26b2bef736adb5d712c2f45fdbd173e89a

Aliases

arxiv: 0704.0640 · arxiv_version: 0704.0640v2 · doi: 10.48550/arxiv.0704.0640 · pith_short_12: O5X4EPIOCHYM · pith_short_16: O5X4EPIOCHYMPG4H · pith_short_8: O5X4EPIO

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/O5X4EPIOCHYMPG4HFV65HONLE2 \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 776fc23d0e11f0c79b872d7dd3b9ab26b2bef736adb5d712c2f45fdbd173e89a

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "8e4ec35f11e036fbad7b78a180cfb96c2f2fee626a45f2fea8c418d2a5960355",
    "cross_cats_sorted": [],
    "license": "",
    "primary_cat": "math.CO",
    "submitted_at": "2007-04-04T19:09:27Z",
    "title_canon_sha256": "98f92ae66b842a859d7ed6e148df8a4e59117d88f073787cac1e0af3b0cadc01"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0704.0640",
    "kind": "arxiv",
    "version": 2
  }
}