Block #339,823

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/2/2014, 8:59:20 AM · Difficulty 10.1297 · 6,464,488 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
69034e3ddbdc00e68dc1a26459596e1cc6932933643fc47df63b555c6fa2c833

Height

#339,823

Difficulty

10.129696

Transactions

8

Size

3.52 KB

Version

2

Bits

0a2133bb

Nonce

184,079

Timestamp

1/2/2014, 8:59:20 AM

Confirmations

6,464,488

Merkle Root

861f1431e74618dd345f72e85edc0b2c94d02b89875f48de1b58706135bbe036
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.

4.955 × 10⁹⁹(100-digit number)
49555729864857537458…44667185118816885919
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
4.955 × 10⁹⁹(100-digit number)
49555729864857537458…44667185118816885919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
9.911 × 10⁹⁹(100-digit number)
99111459729715074917…89334370237633771839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.982 × 10¹⁰⁰(101-digit number)
19822291945943014983…78668740475267543679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
3.964 × 10¹⁰⁰(101-digit number)
39644583891886029966…57337480950535087359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
7.928 × 10¹⁰⁰(101-digit number)
79289167783772059933…14674961901070174719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
1.585 × 10¹⁰¹(102-digit number)
15857833556754411986…29349923802140349439
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
3.171 × 10¹⁰¹(102-digit number)
31715667113508823973…58699847604280698879
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
6.343 × 10¹⁰¹(102-digit number)
63431334227017647947…17399695208561397759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
1.268 × 10¹⁰²(103-digit number)
12686266845403529589…34799390417122795519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
2.537 × 10¹⁰²(103-digit number)
25372533690807059178…69598780834245591039
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 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.

★★☆☆☆
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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,678,549 XPM·at block #6,804,310 · updates every 60s
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