Home/Chain Registry/Block #326,239

Block #326,239

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/23/2013, 3:38:37 PM · Difficulty 10.1941 · 6,473,926 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d0b1fd779592af2c25244b985be6405e8f4f9b71d06cd2b09c3d9673e4889737

Height

#326,239

Difficulty

10.194072

Transactions

10

Size

3.34 KB

Version

2

Bits

0a31aeae

Nonce

28,539

Timestamp

12/23/2013, 3:38:37 PM

Confirmations

6,473,926

Merkle Root

9e6fdd44ab9c681822f93e764a66ab17c8d6befb361718394d6a7f2fadf894df
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.

4.979 × 10⁹⁷(98-digit number)
49793672054996472206…53778240083020502400
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
4.979 × 10⁹⁷(98-digit number)
49793672054996472206…53778240083020502401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.958 × 10⁹⁷(98-digit number)
99587344109992944413…07556480166041004801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.991 × 10⁹⁸(99-digit number)
19917468821998588882…15112960332082009601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.983 × 10⁹⁸(99-digit number)
39834937643997177765…30225920664164019201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.966 × 10⁹⁸(99-digit number)
79669875287994355530…60451841328328038401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.593 × 10⁹⁹(100-digit number)
15933975057598871106…20903682656656076801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.186 × 10⁹⁹(100-digit number)
31867950115197742212…41807365313312153601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.373 × 10⁹⁹(100-digit number)
63735900230395484424…83614730626624307201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.274 × 10¹⁰⁰(101-digit number)
12747180046079096884…67229461253248614401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.549 × 10¹⁰⁰(101-digit number)
25494360092158193769…34458922506497228801
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 Second 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 2CC formula:

2CC: 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 326239

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 d0b1fd779592af2c25244b985be6405e8f4f9b71d06cd2b09c3d9673e4889737

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 #326,239 on Chainz ↗
Circulating Supply:57,645,387 XPM·at block #6,800,164 · updates every 60s
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