Home/Chain Registry/Block #366,641

Block #366,641

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/19/2014, 1:05:20 PM · Difficulty 10.4335 · 6,424,989 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5885f7fc448da40e0081594cc735997cfbf615b66756fbc88258081ff34de5cf

Height

#366,641

Difficulty

10.433480

Transactions

9

Size

2.11 KB

Version

2

Bits

0a6ef88b

Nonce

198,440

Timestamp

1/19/2014, 1:05:20 PM

Confirmations

6,424,989

Merkle Root

6842b9a20d3b40608c1131dd4a76aa28057a01be24c3e9562887a597d03a4ccf
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.

2.300 × 10⁹⁸(99-digit number)
23004424472283048698…13631006377130556400
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
2.300 × 10⁹⁸(99-digit number)
23004424472283048698…13631006377130556401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.600 × 10⁹⁸(99-digit number)
46008848944566097396…27262012754261112801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.201 × 10⁹⁸(99-digit number)
92017697889132194792…54524025508522225601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.840 × 10⁹⁹(100-digit number)
18403539577826438958…09048051017044451201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.680 × 10⁹⁹(100-digit number)
36807079155652877916…18096102034088902401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.361 × 10⁹⁹(100-digit number)
73614158311305755833…36192204068177804801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.472 × 10¹⁰⁰(101-digit number)
14722831662261151166…72384408136355609601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.944 × 10¹⁰⁰(101-digit number)
29445663324522302333…44768816272711219201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.889 × 10¹⁰⁰(101-digit number)
58891326649044604667…89537632545422438401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.177 × 10¹⁰¹(102-digit number)
11778265329808920933…79075265090844876801
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 366641

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 5885f7fc448da40e0081594cc735997cfbf615b66756fbc88258081ff34de5cf

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 #366,641 on Chainz ↗
Circulating Supply:57,576,989 XPM·at block #6,791,629 · updates every 60s
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