Home/Chain Registry/Block #321,352

Block #321,352

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/20/2013, 6:28:52 AM · Difficulty 10.1905 · 6,476,746 confirmations

1CC
Cunningham Chain of the First Kind

A sequence where each prime is double the previous prime plus one.

Block Header
Block Hash
4b55ee2fdbfb0dacca9dc9b0f842ddc067d02e47f696b81ff6f67cccd709f465

Height

#321,352

Difficulty

10.190496

Transactions

9

Size

3.33 KB

Version

2

Bits

0a30c456

Nonce

412,191

Timestamp

12/20/2013, 6:28:52 AM

Confirmations

6,476,746

Merkle Root

669afa1f137e23b480154f10cab7cf398d4d456c6d65925f25a0835c9c0a25c5
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) — it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

5.992 × 10⁹⁰(91-digit number)
59921278747186114681…47694923817774173160
Discovered Prime Numbers
p_k = 2^k × origin − 1

These are the actual prime numbers discovered by this block, computed using the verified Primecoin formula. Each number has been independently confirmed to pass the Fermat primality test. Use the FactorDB links to verify any number independently.

1
origin − 1
5.992 × 10⁹⁰(91-digit number)
59921278747186114681…47694923817774173159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.198 × 10⁹¹(92-digit number)
11984255749437222936…95389847635548346319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.396 × 10⁹¹(92-digit number)
23968511498874445872…90779695271096692639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.793 × 10⁹¹(92-digit number)
47937022997748891744…81559390542193385279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.587 × 10⁹¹(92-digit number)
95874045995497783489…63118781084386770559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.917 × 10⁹²(93-digit number)
19174809199099556697…26237562168773541119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.834 × 10⁹²(93-digit number)
38349618398199113395…52475124337547082239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.669 × 10⁹²(93-digit number)
76699236796398226791…04950248675094164479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.533 × 10⁹³(94-digit number)
15339847359279645358…09900497350188328959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
3.067 × 10⁹³(94-digit number)
30679694718559290716…19800994700376657919
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 10 consecutive prime numbers forming a Cunningham Chain of the First Kind. The prime chain origin — the large number shown above — anchors the chain and is divisible by a primorial (the product of small primes), cryptographically tying these prime numbers to this specific block.

View full Prime Chain Discovery page →
★★☆☆☆
Rarity
UncommonChain length 10
How Primecoin's Proof-of-Work Constructs These Primes

Primecoin stores a value called the prime chain origin in each block. The miner found a large integer such that when divided by a primorial (the product of small primes: 2 × 3 × 5 × 7 × …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial — that divisibility is part of the proof.

Prime Chain Origin = First Prime × Primorial (2·3·5·7·11·…)
Source: Primecoin prime.cpp — CheckPrimeProofOfWork()

This is why the origin has many small prime factors — those factors are the primorial divisor. The chain then extends from the first prime using the 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Verify on a Primecoin Node

Anyone running a Primecoin node can independently verify this block using the following RPC commands. Run these from the primecoin-cli command line or via the debug console in the Primecoin wallet.

1. Get block hash by height
getblockhash 321352

Returns the block hash for a given block height. Use this to confirm the hash shown above matches the chain.

2. Get full block data
getblock 4b55ee2fdbfb0dacca9dc9b0f842ddc067d02e47f696b81ff6f67cccd709f465

Returns the full block header including difficulty, prime chain origin, prime chain type, transaction IDs, and all other fields shown on this page.

How to run these commands: To verify this data independently, open a terminal on your own Primecoin node and run primecoin-cli <command>. Alternatively, open the Primecoin-Qt wallet, go to Help → Debug Window → Console, and type the command directly. The node must be fully synced to this block height for the commands to return results.

Cross-reference on Chainz Explorer

Chainz is an independent Primecoin block explorer. Compare this block's data to verify accuracy.

View Block #321,352 on Chainz ↗
Circulating Supply:57,628,783 XPM·at block #6,798,097 · updates every 60s
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