Home/Chain Registry/Block #392,739

Block #392,739

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 2/6/2014, 4:00:02 PM · Difficulty 10.4407 · 6,432,329 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
8ca49b8c3e9cfe211a04354ee767d4b58cdddf6c3ec109b239ef1e9c8b73b59d

Height

#392,739

Difficulty

10.440664

Transactions

5

Size

1.66 KB

Version

2

Bits

0a70cf5d

Nonce

53,453

Timestamp

2/6/2014, 4:00:02 PM

Confirmations

6,432,329

Merkle Root

eef9372bfd875b2ff19e62e520be69a61e11bb7e3dde568ffae4626908052148
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.

5.315 × 10⁹⁴(95-digit number)
53152913532642830707…30386214714837455740
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
5.315 × 10⁹⁴(95-digit number)
53152913532642830707…30386214714837455739
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.063 × 10⁹⁵(96-digit number)
10630582706528566141…60772429429674911479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.126 × 10⁹⁵(96-digit number)
21261165413057132282…21544858859349822959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.252 × 10⁹⁵(96-digit number)
42522330826114264565…43089717718699645919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.504 × 10⁹⁵(96-digit number)
85044661652228529131…86179435437399291839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.700 × 10⁹⁶(97-digit number)
17008932330445705826…72358870874798583679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.401 × 10⁹⁶(97-digit number)
34017864660891411652…44717741749597167359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.803 × 10⁹⁶(97-digit number)
68035729321782823304…89435483499194334719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.360 × 10⁹⁷(98-digit number)
13607145864356564660…78870966998388669439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.721 × 10⁹⁷(98-digit number)
27214291728713129321…57741933996777338879
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 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
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 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 392739

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 8ca49b8c3e9cfe211a04354ee767d4b58cdddf6c3ec109b239ef1e9c8b73b59d

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 #392,739 on Chainz ↗
Circulating Supply:57,844,631 XPM·at block #6,825,067 · updates every 60s
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