Home/Chain Registry/Block #294,056

Block #294,056

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/4/2013, 4:13:29 PM · Difficulty 9.9909 · 6,545,519 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
25043bb2b95e2dca64927ae51d0cab071953e91a95def4b657a972cc5dc73e5f

Height

#294,056

Difficulty

9.990861

Transactions

12

Size

2.58 KB

Version

2

Bits

09fda910

Nonce

61,078

Timestamp

12/4/2013, 4:13:29 PM

Confirmations

6,545,519

Merkle Root

fc58ced778587050459f3841c311d9ba2e9a065ae23d51e31c3f73892ab41cd8
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.

1.002 × 10⁹¹(92-digit number)
10028951388464063361…67411111954183590560
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
1.002 × 10⁹¹(92-digit number)
10028951388464063361…67411111954183590561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.005 × 10⁹¹(92-digit number)
20057902776928126723…34822223908367181121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.011 × 10⁹¹(92-digit number)
40115805553856253447…69644447816734362241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.023 × 10⁹¹(92-digit number)
80231611107712506894…39288895633468724481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.604 × 10⁹²(93-digit number)
16046322221542501378…78577791266937448961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.209 × 10⁹²(93-digit number)
32092644443085002757…57155582533874897921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.418 × 10⁹²(93-digit number)
64185288886170005515…14311165067749795841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.283 × 10⁹³(94-digit number)
12837057777234001103…28622330135499591681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.567 × 10⁹³(94-digit number)
25674115554468002206…57244660270999183361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.134 × 10⁹³(94-digit number)
51348231108936004412…14489320541998366721
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 294056

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 25043bb2b95e2dca64927ae51d0cab071953e91a95def4b657a972cc5dc73e5f

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 #294,056 on Chainz ↗
Circulating Supply:57,960,886 XPM·at block #6,839,574 · updates every 60s
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