Block #330,132

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/26/2013, 11:17:55 AM · Difficulty 10.1680 · 6,480,642 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f38ff1309db93ab2face9addd81e2fbd865303528ac295e34b4840777b9f7542

Height

#330,132

Difficulty

10.168036

Transactions

18

Size

7.36 KB

Version

2

Bits

0a2b0469

Nonce

123

Timestamp

12/26/2013, 11:17:55 AM

Confirmations

6,480,642

Merkle Root

7e383ad18e96ee97024931b0ef3f8689e78fd94262e0f0aa176fa7d1d9774de0
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.

1.029 × 10⁹⁹(100-digit number)
10291391797204849532…21519376826929190721
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
1.029 × 10⁹⁹(100-digit number)
10291391797204849532…21519376826929190721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.058 × 10⁹⁹(100-digit number)
20582783594409699064…43038753653858381441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.116 × 10⁹⁹(100-digit number)
41165567188819398129…86077507307716762881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.233 × 10⁹⁹(100-digit number)
82331134377638796259…72155014615433525761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.646 × 10¹⁰⁰(101-digit number)
16466226875527759251…44310029230867051521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.293 × 10¹⁰⁰(101-digit number)
32932453751055518503…88620058461734103041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.586 × 10¹⁰⁰(101-digit number)
65864907502111037007…77240116923468206081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.317 × 10¹⁰¹(102-digit number)
13172981500422207401…54480233846936412161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.634 × 10¹⁰¹(102-digit number)
26345963000844414802…08960467693872824321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.269 × 10¹⁰¹(102-digit number)
52691926001688829605…17920935387745648641
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:57,730,288 XPM·at block #6,810,773 · updates every 60s
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