Home/Chain Registry/Block #845,654

Block #845,654

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 12/9/2014, 1:00:44 AM · Difficulty 10.9725 · 5,992,678 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3e10cda00e5c5c9890fa666f0b0594f5a049efd9df622969b8732e13f342f744

Height

#845,654

Difficulty

10.972468

Transactions

8

Size

1.77 KB

Version

2

Bits

0af8f3a7

Nonce

562,786,773

Timestamp

12/9/2014, 1:00:44 AM

Confirmations

5,992,678

Merkle Root

318d8e09596d60cacb3fb584342b8361d041714d973020d87c09f8f93dce19b8
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.

2.041 × 10⁹⁴(95-digit number)
20412170103800029808…01694567954605150200
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
2.041 × 10⁹⁴(95-digit number)
20412170103800029808…01694567954605150199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.082 × 10⁹⁴(95-digit number)
40824340207600059617…03389135909210300399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
8.164 × 10⁹⁴(95-digit number)
81648680415200119235…06778271818420600799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.632 × 10⁹⁵(96-digit number)
16329736083040023847…13556543636841201599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.265 × 10⁹⁵(96-digit number)
32659472166080047694…27113087273682403199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.531 × 10⁹⁵(96-digit number)
65318944332160095388…54226174547364806399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.306 × 10⁹⁶(97-digit number)
13063788866432019077…08452349094729612799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.612 × 10⁹⁶(97-digit number)
26127577732864038155…16904698189459225599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
5.225 × 10⁹⁶(97-digit number)
52255155465728076310…33809396378918451199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.045 × 10⁹⁷(98-digit number)
10451031093145615262…67618792757836902399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
2.090 × 10⁹⁷(98-digit number)
20902062186291230524…35237585515673804799
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 845654

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 3e10cda00e5c5c9890fa666f0b0594f5a049efd9df622969b8732e13f342f744

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 #845,654 on Chainz ↗
Circulating Supply:57,950,933 XPM·at block #6,838,331 · updates every 60s
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