Home/Chain Registry/Block #374,894

Block #374,894

2CCLength 10β˜…β˜…β˜†β˜†β˜†

Cunningham Chain of the Second Kind Β· Discovered 1/25/2014, 9:04:31 AM Β· Difficulty 10.4181 Β· 6,437,701 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cdd9a965f82ad48eb5e92e31b7dc186b8ca180cd0573d7bccfe9252cf6d50386

Height

#374,894

Difficulty

10.418082

Transactions

1

Size

205 B

Version

2

Bits

0a6b0773

Nonce

4,083

Timestamp

1/25/2014, 9:04:31 AM

Confirmations

6,437,701

Merkle Root

032979927413612e895f65ae444902abb64a818a80bb47167dc6db711dc1d5e2
Transactions (1)
1 in β†’ 1 out9.2000 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.

7.965 Γ— 10⁹²(93-digit number)
79650876672191593694…39356494380889520640
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
7.965 Γ— 10⁹²(93-digit number)
79650876672191593694…39356494380889520641
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
2
2^1 Γ— origin + 1
1.593 Γ— 10⁹³(94-digit number)
15930175334438318738…78712988761779041281
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
3
2^2 Γ— origin + 1
3.186 Γ— 10⁹³(94-digit number)
31860350668876637477…57425977523558082561
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
4
2^3 Γ— origin + 1
6.372 Γ— 10⁹³(94-digit number)
63720701337753274955…14851955047116165121
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
5
2^4 Γ— origin + 1
1.274 Γ— 10⁹⁴(95-digit number)
12744140267550654991…29703910094232330241
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
6
2^5 Γ— origin + 1
2.548 Γ— 10⁹⁴(95-digit number)
25488280535101309982…59407820188464660481
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
7
2^6 Γ— origin + 1
5.097 Γ— 10⁹⁴(95-digit number)
50976561070202619964…18815640376929320961
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
8
2^7 Γ— origin + 1
1.019 Γ— 10⁹⁡(96-digit number)
10195312214040523992…37631280753858641921
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
9
2^8 Γ— origin + 1
2.039 Γ— 10⁹⁡(96-digit number)
20390624428081047985…75262561507717283841
Verify on FactorDB β†—Wolfram Alpha β†—
Γ—2βˆ’1 β†’
10
2^9 Γ— origin + 1
4.078 Γ— 10⁹⁡(96-digit number)
40781248856162095971…50525123015434567681
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 374894

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 cdd9a965f82ad48eb5e92e31b7dc186b8ca180cd0573d7bccfe9252cf6d50386

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 #374,894 on Chainz β†—
Circulating Supply:57,744,794 XPMΒ·at block #6,812,594 Β· updates every 60s
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