Home/Chain Registry/Block #292,312

Block #292,312

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 12/3/2013, 4:05:50 PM Β· Difficulty 9.9902 Β· 6,520,387 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
fc2b24c4df0bbf62fea3d03d74017985ceffbfb99b83ca6f5573660b9e3122ef

Height

#292,312

Difficulty

9.990248

Transactions

1

Size

206 B

Version

2

Bits

09fd80e4

Nonce

8,058

Timestamp

12/3/2013, 4:05:50 PM

Confirmations

6,520,387

Merkle Root

c62d6fdd96fb2c74be3d0bf7013456d09f44441ee439bce82ef85871147e459d
Transactions (1)
1 in β†’ 1 out10.0000 XPM116 B
Prime Chain Origin

This is the prime chain origin stored in the block header. It is a composite number (not prime itself) β€” it equals the first prime in the chain multiplied by a primorial. The origin anchors the entire chain to this specific block.

3.065 Γ— 10⁹⁡(96-digit number)
30655703331836794726…72242440075897083840
Discovered Prime Numbers
p_k = 2^k Γ— 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
3.065 Γ— 10⁹⁡(96-digit number)
30655703331836794726…72242440075897083841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
6.131 Γ— 10⁹⁡(96-digit number)
61311406663673589452…44484880151794167681
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
1.226 Γ— 10⁹⁢(97-digit number)
12262281332734717890…88969760303588335361
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
2.452 Γ— 10⁹⁢(97-digit number)
24524562665469435781…77939520607176670721
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
4.904 Γ— 10⁹⁢(97-digit number)
49049125330938871562…55879041214353341441
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
9.809 Γ— 10⁹⁢(97-digit number)
98098250661877743124…11758082428706682881
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
1.961 Γ— 10⁹⁷(98-digit number)
19619650132375548624…23516164857413365761
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
3.923 Γ— 10⁹⁷(98-digit number)
39239300264751097249…47032329714826731521
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
7.847 Γ— 10⁹⁷(98-digit number)
78478600529502194499…94064659429653463041
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
1.569 Γ— 10⁹⁸(99-digit number)
15695720105900438899…88129318859306926081
Verify on FactorDB β†—Wolfram Alpha β†—

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 β€” the large number shown above β€” 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 β†’
β˜…β˜…β˜†β˜†β˜†
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 Γ— 3 Γ— 5 Γ— 7 Γ— …), the result is the first prime in the chain. The origin is deliberately divisible by this primorial β€” that divisibility is part of the proof.

Prime Chain Origin = First Prime Γ— Primorial (2Β·3Β·5Β·7Β·11·…)
Source: Primecoin prime.cpp β€” CheckPrimeProofOfWork()

This is why the origin has many small prime factors β€” those factors are the primorial divisor. The chain then extends from the first prime using the 2CC formula:

2CC: p₁ (first prime), pβ‚‚ = 2p₁ βˆ’ 1, p₃ = 2pβ‚‚ βˆ’ 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 292312

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 fc2b24c4df0bbf62fea3d03d74017985ceffbfb99b83ca6f5573660b9e3122ef

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 β†’ Debug Window β†’ 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 #292,312 on Chainz β†—
Circulating Supply:57,745,628 XPMΒ·at block #6,812,698 Β· updates every 60s
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