Home/Chain Registry/Block #474,737

Block #474,737

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/4/2014, 6:24:56 PM · Difficulty 10.4557 · 6,356,607 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f4656057090d17c64f30b8d7ffb288bb938bf98e20620c1f39d2becd57c527c7

Height

#474,737

Difficulty

10.455696

Transactions

5

Size

1.66 KB

Version

2

Bits

0a74a87b

Nonce

21,306,371

Timestamp

4/4/2014, 6:24:56 PM

Confirmations

6,356,607

Merkle Root

8cc58a35283931b8a11b9a71783b616188871e9255525927d2f64fbd7d4ba6d9
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.

5.614 × 10⁹³(94-digit number)
56149263426985296136…29871288265460165230
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
5.614 × 10⁹³(94-digit number)
56149263426985296136…29871288265460165231
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.122 × 10⁹⁴(95-digit number)
11229852685397059227…59742576530920330461
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.245 × 10⁹⁴(95-digit number)
22459705370794118454…19485153061840660921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.491 × 10⁹⁴(95-digit number)
44919410741588236908…38970306123681321841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.983 × 10⁹⁴(95-digit number)
89838821483176473817…77940612247362643681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.796 × 10⁹⁵(96-digit number)
17967764296635294763…55881224494725287361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.593 × 10⁹⁵(96-digit number)
35935528593270589527…11762448989450574721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.187 × 10⁹⁵(96-digit number)
71871057186541179054…23524897978901149441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.437 × 10⁹⁶(97-digit number)
14374211437308235810…47049795957802298881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.874 × 10⁹⁶(97-digit number)
28748422874616471621…94099591915604597761
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 474737

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 f4656057090d17c64f30b8d7ffb288bb938bf98e20620c1f39d2becd57c527c7

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 #474,737 on Chainz ↗
Circulating Supply:57,894,906 XPM·at block #6,831,343 · updates every 60s
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