Home/Chain Registry/Block #340,100

Block #340,100

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/2/2014, 1:51:48 PM · Difficulty 10.1270 · 6,491,659 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ca981fa325423a29db1e634c9b1fc6fc13b76e59ee88fd6053ce45baf3c83cea

Height

#340,100

Difficulty

10.127008

Transactions

6

Size

1.73 KB

Version

2

Bits

0a2083a1

Nonce

46,992

Timestamp

1/2/2014, 1:51:48 PM

Confirmations

6,491,659

Merkle Root

fbe951add3ddba8894e93ffc0420780be09ee0654e2b79e93ba360a80b85f5d7
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.

1.461 × 10⁹⁶(97-digit number)
14612817924148516292…44810446625257854720
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
1.461 × 10⁹⁶(97-digit number)
14612817924148516292…44810446625257854721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.922 × 10⁹⁶(97-digit number)
29225635848297032585…89620893250515709441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.845 × 10⁹⁶(97-digit number)
58451271696594065171…79241786501031418881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.169 × 10⁹⁷(98-digit number)
11690254339318813034…58483573002062837761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.338 × 10⁹⁷(98-digit number)
23380508678637626068…16967146004125675521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.676 × 10⁹⁷(98-digit number)
46761017357275252136…33934292008251351041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.352 × 10⁹⁷(98-digit number)
93522034714550504273…67868584016502702081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.870 × 10⁹⁸(99-digit number)
18704406942910100854…35737168033005404161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.740 × 10⁹⁸(99-digit number)
37408813885820201709…71474336066010808321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.481 × 10⁹⁸(99-digit number)
74817627771640403419…42948672132021616641
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 340100

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 ca981fa325423a29db1e634c9b1fc6fc13b76e59ee88fd6053ce45baf3c83cea

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 #340,100 on Chainz ↗
Circulating Supply:57,898,181 XPM·at block #6,831,758 · updates every 60s
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