Home/Chain Registry/Block #379,820

Block #379,820

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/28/2014, 7:09:17 PM · Difficulty 10.4196 · 6,434,222 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
085e36b3b6a8a9cc1b0b2c967fc0094e574aff092ad02b4820c1f449f12e47ca

Height

#379,820

Difficulty

10.419562

Transactions

12

Size

3.22 KB

Version

2

Bits

0a6b686c

Nonce

3,599

Timestamp

1/28/2014, 7:09:17 PM

Confirmations

6,434,222

Merkle Root

3429d9692f6dd81c7eab2011ae1bd8d70b603ffb0dbef6e810c98645901d5ba3
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.

1.295 × 10⁹⁴(95-digit number)
12956555742358097087…45768949581852211200
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
1.295 × 10⁹⁴(95-digit number)
12956555742358097087…45768949581852211201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.591 × 10⁹⁴(95-digit number)
25913111484716194175…91537899163704422401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.182 × 10⁹⁴(95-digit number)
51826222969432388350…83075798327408844801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.036 × 10⁹⁵(96-digit number)
10365244593886477670…66151596654817689601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.073 × 10⁹⁵(96-digit number)
20730489187772955340…32303193309635379201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.146 × 10⁹⁵(96-digit number)
41460978375545910680…64606386619270758401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
8.292 × 10⁹⁵(96-digit number)
82921956751091821360…29212773238541516801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.658 × 10⁹⁶(97-digit number)
16584391350218364272…58425546477083033601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.316 × 10⁹⁶(97-digit number)
33168782700436728544…16851092954166067201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.633 × 10⁹⁶(97-digit number)
66337565400873457088…33702185908332134401
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 379820

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 085e36b3b6a8a9cc1b0b2c967fc0094e574aff092ad02b4820c1f449f12e47ca

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 #379,820 on Chainz ↗
Circulating Supply:57,756,411 XPM·at block #6,814,041 · updates every 60s
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