Home/Chain Registry/Block #206,119

Block #206,119

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 10/12/2013, 2:38:12 PM · Difficulty 9.9006 · 6,591,506 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8e9445a4886aa88871d558ac688fdd28d535c1bc5f3f1d4a3021b842bedf4876

Height

#206,119

Difficulty

9.900637

Transactions

5

Size

2.09 KB

Version

2

Bits

09e69022

Nonce

262,006

Timestamp

10/12/2013, 2:38:12 PM

Confirmations

6,591,506

Merkle Root

9e3a4e51f0ef66581f5f6edae79ddf7e2942be5cc5bfe7af72f613fcb2336d87
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.

3.374 × 10⁹²(93-digit number)
33745049192310951406…26795627203562730400
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
3.374 × 10⁹²(93-digit number)
33745049192310951406…26795627203562730401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.749 × 10⁹²(93-digit number)
67490098384621902813…53591254407125460801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.349 × 10⁹³(94-digit number)
13498019676924380562…07182508814250921601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.699 × 10⁹³(94-digit number)
26996039353848761125…14365017628501843201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.399 × 10⁹³(94-digit number)
53992078707697522250…28730035257003686401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.079 × 10⁹⁴(95-digit number)
10798415741539504450…57460070514007372801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.159 × 10⁹⁴(95-digit number)
21596831483079008900…14920141028014745601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.319 × 10⁹⁴(95-digit number)
43193662966158017800…29840282056029491201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.638 × 10⁹⁴(95-digit number)
86387325932316035601…59680564112058982401
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9
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 206119

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 8e9445a4886aa88871d558ac688fdd28d535c1bc5f3f1d4a3021b842bedf4876

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 #206,119 on Chainz ↗
Circulating Supply:57,624,986 XPM·at block #6,797,624 · updates every 60s
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