Block #444,825

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/15/2014, 12:08:26 PM · Difficulty 10.3509 · 6,348,247 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1733b36966f47c810ce858eb35ee32579c83285cf3a9ad71b5f9b0260b38f4a4

Height

#444,825

Difficulty

10.350885

Transactions

2

Size

1.10 KB

Version

2

Bits

0a59d396

Nonce

143,708

Timestamp

3/15/2014, 12:08:26 PM

Confirmations

6,348,247

Merkle Root

ae6557a390157d488d0dd8f601e90ac2c7830dedc23e76916c32c332219a6dde
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.

1.137 × 10⁹⁹(100-digit number)
11371689064777958091…80732523915408955841
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
1.137 × 10⁹⁹(100-digit number)
11371689064777958091…80732523915408955841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.274 × 10⁹⁹(100-digit number)
22743378129555916182…61465047830817911681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.548 × 10⁹⁹(100-digit number)
45486756259111832365…22930095661635823361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.097 × 10⁹⁹(100-digit number)
90973512518223664731…45860191323271646721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.819 × 10¹⁰⁰(101-digit number)
18194702503644732946…91720382646543293441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.638 × 10¹⁰⁰(101-digit number)
36389405007289465892…83440765293086586881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.277 × 10¹⁰⁰(101-digit number)
72778810014578931785…66881530586173173761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.455 × 10¹⁰¹(102-digit number)
14555762002915786357…33763061172346347521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.911 × 10¹⁰¹(102-digit number)
29111524005831572714…67526122344692695041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.822 × 10¹⁰¹(102-digit number)
58223048011663145428…35052244689385390081
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.

★★☆☆☆
Rarity
UncommonChain length 10

Roughly 1 in 100 blocks. Solid but expected in a healthy network.

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, …
Circulating Supply:57,588,569 XPM·at block #6,793,071 · updates every 60s
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