Home/Chain Registry/Block #212,083

Block #212,083

1CCLength 9★☆☆☆☆

Cunningham Chain of the First Kind · Discovered 10/16/2013, 1:56:34 AM · Difficulty 9.9182 · 6,586,725 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
7ca3249b4047bf33833814db9ecf55e67d34f93368141a87b8142ece47ec9339

Height

#212,083

Difficulty

9.918223

Transactions

13

Size

3.53 KB

Version

2

Bits

09eb10a5

Nonce

59,864

Timestamp

10/16/2013, 1:56:34 AM

Confirmations

6,586,725

Merkle Root

cb786bed8d86652a681889fb6996d8066d6cd95162cb6bf570068af53bf57285
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.

5.852 × 10⁹²(93-digit number)
58525670751086738695…81359409028846030140
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
5.852 × 10⁹²(93-digit number)
58525670751086738695…81359409028846030139
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.170 × 10⁹³(94-digit number)
11705134150217347739…62718818057692060279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.341 × 10⁹³(94-digit number)
23410268300434695478…25437636115384120559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.682 × 10⁹³(94-digit number)
46820536600869390956…50875272230768241119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
9.364 × 10⁹³(94-digit number)
93641073201738781912…01750544461536482239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.872 × 10⁹⁴(95-digit number)
18728214640347756382…03501088923072964479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.745 × 10⁹⁴(95-digit number)
37456429280695512764…07002177846145928959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
7.491 × 10⁹⁴(95-digit number)
74912858561391025529…14004355692291857919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.498 × 10⁹⁵(96-digit number)
14982571712278205105…28008711384583715839
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 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
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 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 212083

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 7ca3249b4047bf33833814db9ecf55e67d34f93368141a87b8142ece47ec9339

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 #212,083 on Chainz ↗
Circulating Supply:57,634,490 XPM·at block #6,798,807 · updates every 60s
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