Block #332,739

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/28/2013, 6:58:55 AM · Difficulty 10.1669 · 6,480,142 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
0e48b86bb84e3638e1f6a36334dd061a51bd9a1f5a10ba3f8e75989d4d80673e

Height

#332,739

Difficulty

10.166877

Transactions

14

Size

9.13 KB

Version

2

Bits

0a2ab86d

Nonce

79,903

Timestamp

12/28/2013, 6:58:55 AM

Confirmations

6,480,142

Merkle Root

1e7f6dc51bc4c2eb0e3078e0f62b5c2a34ce05f1b2ce02856bdc5f1cd06835f0
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.

1.411 × 10¹⁰⁵(106-digit number)
14116337573408667415…10304738398681719681
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
1.411 × 10¹⁰⁵(106-digit number)
14116337573408667415…10304738398681719681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.823 × 10¹⁰⁵(106-digit number)
28232675146817334830…20609476797363439361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.646 × 10¹⁰⁵(106-digit number)
56465350293634669661…41218953594726878721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.129 × 10¹⁰⁶(107-digit number)
11293070058726933932…82437907189453757441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.258 × 10¹⁰⁶(107-digit number)
22586140117453867864…64875814378907514881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.517 × 10¹⁰⁶(107-digit number)
45172280234907735729…29751628757815029761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.034 × 10¹⁰⁶(107-digit number)
90344560469815471458…59503257515630059521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.806 × 10¹⁰⁷(108-digit number)
18068912093963094291…19006515031260119041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.613 × 10¹⁰⁷(108-digit number)
36137824187926188583…38013030062520238081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.227 × 10¹⁰⁷(108-digit number)
72275648375852377167…76026060125040476161
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:57,747,079 XPM·at block #6,812,880 · updates every 60s
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