Home/Chain Registry/Block #857,812

Block #857,812

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/18/2014, 2:58:59 AM · Difficulty 10.9674 · 5,983,888 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
249d95a53b7874d9ac58fdc89119c1eb94e8d16451175402470d9faa67bb9632

Height

#857,812

Difficulty

10.967363

Transactions

13

Size

2.85 KB

Version

2

Bits

0af7a514

Nonce

313,848,079

Timestamp

12/18/2014, 2:58:59 AM

Confirmations

5,983,888

Merkle Root

739524a610f7ebe9c7088c78e1ea804870f9dca47fd9b145518d5fb173d9fe94
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.

5.385 × 10⁹⁵(96-digit number)
53859002891654592512…90138859026254115840
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
5.385 × 10⁹⁵(96-digit number)
53859002891654592512…90138859026254115839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
1.077 × 10⁹⁶(97-digit number)
10771800578330918502…80277718052508231679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
2.154 × 10⁹⁶(97-digit number)
21543601156661837004…60555436105016463359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
4.308 × 10⁹⁶(97-digit number)
43087202313323674009…21110872210032926719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
8.617 × 10⁹⁶(97-digit number)
86174404626647348019…42221744420065853439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.723 × 10⁹⁷(98-digit number)
17234880925329469603…84443488840131706879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.446 × 10⁹⁷(98-digit number)
34469761850658939207…68886977680263413759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.893 × 10⁹⁷(98-digit number)
68939523701317878415…37773955360526827519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.378 × 10⁹⁸(99-digit number)
13787904740263575683…75547910721053655039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.757 × 10⁹⁸(99-digit number)
27575809480527151366…51095821442107310079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
5.515 × 10⁹⁸(99-digit number)
55151618961054302732…02191642884214620159
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11
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 857812

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 249d95a53b7874d9ac58fdc89119c1eb94e8d16451175402470d9faa67bb9632

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 #857,812 on Chainz ↗
Circulating Supply:57,977,979 XPM·at block #6,841,699 · updates every 60s
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