Home/Chain Registry/Block #424,715

Block #424,715

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/1/2014, 9:57:16 AM · Difficulty 10.3621 · 6,400,379 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
664ecd38542ef20484ff87b8e65121663429657b0d2a2532fa2139be0d9d5841

Height

#424,715

Difficulty

10.362089

Transactions

7

Size

1.52 KB

Version

2

Bits

0a5cb1e1

Nonce

285,178

Timestamp

3/1/2014, 9:57:16 AM

Confirmations

6,400,379

Merkle Root

9a496255b6fc88ba74fec6d6ea8af7990b517a09fb940d651ceaec50e105cb5a
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.

4.701 × 10⁹²(93-digit number)
47013317241410817943…55367473280846873600
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
4.701 × 10⁹²(93-digit number)
47013317241410817943…55367473280846873601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
9.402 × 10⁹²(93-digit number)
94026634482821635886…10734946561693747201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.880 × 10⁹³(94-digit number)
18805326896564327177…21469893123387494401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
3.761 × 10⁹³(94-digit number)
37610653793128654354…42939786246774988801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
7.522 × 10⁹³(94-digit number)
75221307586257308709…85879572493549977601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.504 × 10⁹⁴(95-digit number)
15044261517251461741…71759144987099955201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.008 × 10⁹⁴(95-digit number)
30088523034502923483…43518289974199910401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.017 × 10⁹⁴(95-digit number)
60177046069005846967…87036579948399820801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.203 × 10⁹⁵(96-digit number)
12035409213801169393…74073159896799641601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.407 × 10⁹⁵(96-digit number)
24070818427602338786…48146319793599283201
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 424715

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 664ecd38542ef20484ff87b8e65121663429657b0d2a2532fa2139be0d9d5841

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 #424,715 on Chainz ↗
Circulating Supply:57,844,832 XPM·at block #6,825,093 · updates every 60s
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