Home/Chain Registry/Block #386,412

Block #386,412

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 2/2/2014, 11:08:19 AM · Difficulty 10.4074 · 6,408,036 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cdbe54c6b2f3d320d6d7a6f3d170b6745c9dfbbed6cbdb84d7b21e9d30e58b7a

Height

#386,412

Difficulty

10.407392

Transactions

6

Size

1.69 KB

Version

2

Bits

0a684ad9

Nonce

1,072,864

Timestamp

2/2/2014, 11:08:19 AM

Confirmations

6,408,036

Merkle Root

2ceab990277a0e00479fa3501ef71c13c69ac816c8d55178fe2b7d5dc6edb67f
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.

1.704 × 10⁹⁸(99-digit number)
17049108718149264894…53646968907056704000
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
1.704 × 10⁹⁸(99-digit number)
17049108718149264894…53646968907056704001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
3.409 × 10⁹⁸(99-digit number)
34098217436298529788…07293937814113408001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
6.819 × 10⁹⁸(99-digit number)
68196434872597059576…14587875628226816001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.363 × 10⁹⁹(100-digit number)
13639286974519411915…29175751256453632001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.727 × 10⁹⁹(100-digit number)
27278573949038823830…58351502512907264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
5.455 × 10⁹⁹(100-digit number)
54557147898077647661…16703005025814528001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.091 × 10¹⁰⁰(101-digit number)
10911429579615529532…33406010051629056001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.182 × 10¹⁰⁰(101-digit number)
21822859159231059064…66812020103258112001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
4.364 × 10¹⁰⁰(101-digit number)
43645718318462118128…33624040206516224001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
8.729 × 10¹⁰⁰(101-digit number)
87291436636924236257…67248080413032448001
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 386412

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 cdbe54c6b2f3d320d6d7a6f3d170b6745c9dfbbed6cbdb84d7b21e9d30e58b7a

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 #386,412 on Chainz ↗
Circulating Supply:57,599,623 XPM·at block #6,794,447 · updates every 60s
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