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Home/Chain Registry/Block #844,952

Block #844,952

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 12/8/2014, 12:41:06 PM Β· Difficulty 10.9727 Β· 6,000,444 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f78fd75b229f7ac51573beb0dd5b4be3eee6d90cfadcc40bce63f9b5b2dfea0d
View on Chainz β†—

Height

#844,952

Difficulty

10.972651

Transactions

1

Size

207 B

Version

2

Bits

0af8ffac

Nonce

2,583,849,722

Timestamp

12/8/2014, 12:41:06 PM

Confirmations

6,000,444

Merkle Root

0f8b465a2735e2f7187e24c9f09d748d2795a14b99402d5df7884d70c575b02b
Transactions (1)
Coinbase0f8b465a2735e2…884d70c575b02b
1 in β†’ 1 out8.2900 XPM116 B
ANSXnLY2…Sd25TjkD
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.

7.369 Γ— 10⁹⁢(97-digit number)
73694032014519346115…33837188047027507200
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
7.369 Γ— 10⁹⁢(97-digit number)
73694032014519346115…33837188047027507201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
1.473 Γ— 10⁹⁷(98-digit number)
14738806402903869223…67674376094055014401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
2.947 Γ— 10⁹⁷(98-digit number)
29477612805807738446…35348752188110028801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
5.895 Γ— 10⁹⁷(98-digit number)
58955225611615476892…70697504376220057601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
1.179 Γ— 10⁹⁸(99-digit number)
11791045122323095378…41395008752440115201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
2.358 Γ— 10⁹⁸(99-digit number)
23582090244646190756…82790017504880230401
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
4.716 Γ— 10⁹⁸(99-digit number)
47164180489292381513…65580035009760460801
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
9.432 Γ— 10⁹⁸(99-digit number)
94328360978584763027…31160070019520921601
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
1.886 Γ— 10⁹⁹(100-digit number)
18865672195716952605…62320140039041843201
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
3.773 Γ— 10⁹⁹(100-digit number)
37731344391433905211…24640280078083686401
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 844952

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 f78fd75b229f7ac51573beb0dd5b4be3eee6d90cfadcc40bce63f9b5b2dfea0d

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 #844,952 on Chainz β†—
Circulating Supply:58,007,615 XPMΒ·at block #6,845,395 Β· updates every 60s
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