Home/Chain Registry/Block #942,346

Block #942,346

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 2/18/2015, 9:29:03 PM · Difficulty 10.9012 · 5,900,589 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
6863bb743776ffb4d8276b0b48efef6c6eb735119c87af01e6fbd68834df0a9d

Height

#942,346

Difficulty

10.901158

Transactions

3

Size

954 B

Version

2

Bits

0ae6b24f

Nonce

446,568,723

Timestamp

2/18/2015, 9:29:03 PM

Confirmations

5,900,589

Merkle Root

345b256e25e293761c6dba70ef34572974736889f4859b79c6af9ed86d644c7e
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.

3.559 × 10⁹⁷(98-digit number)
35594752790108587816…74374332655379865600
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
3.559 × 10⁹⁷(98-digit number)
35594752790108587816…74374332655379865599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
7.118 × 10⁹⁷(98-digit number)
71189505580217175633…48748665310759731199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.423 × 10⁹⁸(99-digit number)
14237901116043435126…97497330621519462399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.847 × 10⁹⁸(99-digit number)
28475802232086870253…94994661243038924799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
5.695 × 10⁹⁸(99-digit number)
56951604464173740506…89989322486077849599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.139 × 10⁹⁹(100-digit number)
11390320892834748101…79978644972155699199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
2.278 × 10⁹⁹(100-digit number)
22780641785669496202…59957289944311398399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
4.556 × 10⁹⁹(100-digit number)
45561283571338992405…19914579888622796799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
9.112 × 10⁹⁹(100-digit number)
91122567142677984810…39829159777245593599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.822 × 10¹⁰⁰(101-digit number)
18224513428535596962…79658319554491187199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
3.644 × 10¹⁰⁰(101-digit number)
36449026857071193924…59316639108982374399
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 consecutive prime numbers forming a Cunningham Chain of the First 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
RareChain length 11
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 1CC formula:

1CC: 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 942346

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 6863bb743776ffb4d8276b0b48efef6c6eb735119c87af01e6fbd68834df0a9d

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 #942,346 on Chainz ↗
Circulating Supply:57,987,829 XPM·at block #6,842,934 · updates every 60s
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