Home/Chain Registry/Block #326,013

Block #326,013

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 12/23/2013, 11:46:22 AM · Difficulty 10.1951 · 6,474,712 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
899fbc2c5df1eb945d5dacc8bd945b5891457fa81dbe41cc904121fa3ce927c2

Height

#326,013

Difficulty

10.195064

Transactions

9

Size

2.76 KB

Version

2

Bits

0a31efb1

Nonce

5,489

Timestamp

12/23/2013, 11:46:22 AM

Confirmations

6,474,712

Merkle Root

60e40d1f3c3d4abaaaeb6163409c7e24d5418dc6556300bdc93a0bbedca8f824
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.

3.572 × 10⁹⁶(97-digit number)
35728262053591085425…55116351162189018080
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
3.572 × 10⁹⁶(97-digit number)
35728262053591085425…55116351162189018079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.145 × 10⁹⁶(97-digit number)
71456524107182170851…10232702324378036159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.429 × 10⁹⁷(98-digit number)
14291304821436434170…20465404648756072319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.858 × 10⁹⁷(98-digit number)
28582609642872868340…40930809297512144639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.716 × 10⁹⁷(98-digit number)
57165219285745736681…81861618595024289279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.143 × 10⁹⁸(99-digit number)
11433043857149147336…63723237190048578559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.286 × 10⁹⁸(99-digit number)
22866087714298294672…27446474380097157119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.573 × 10⁹⁸(99-digit number)
45732175428596589344…54892948760194314239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.146 × 10⁹⁸(99-digit number)
91464350857193178689…09785897520388628479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.829 × 10⁹⁹(100-digit number)
18292870171438635737…19571795040777256959
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 326013

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 899fbc2c5df1eb945d5dacc8bd945b5891457fa81dbe41cc904121fa3ce927c2

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 #326,013 on Chainz ↗
Circulating Supply:57,649,869 XPM·at block #6,800,724 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.