Block #432,386

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/6/2014, 8:51:56 PM · Difficulty 10.3428 · 6,361,824 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
9df3fc766e54b416bae109b80f6c3574160297876f75c240760f8bba86a96c19

Height

#432,386

Difficulty

10.342842

Transactions

7

Size

2.40 KB

Version

2

Bits

0a57c47b

Nonce

18,023

Timestamp

3/6/2014, 8:51:56 PM

Confirmations

6,361,824

Merkle Root

bc84fbe51438cf721dc4a03a31a361d2fe73e60953bcb231f672f56272467f7d
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.

3.404 × 10⁹⁸(99-digit number)
34042261609509822610…84521312438184544001
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
3.404 × 10⁹⁸(99-digit number)
34042261609509822610…84521312438184544001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.808 × 10⁹⁸(99-digit number)
68084523219019645220…69042624876369088001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.361 × 10⁹⁹(100-digit number)
13616904643803929044…38085249752738176001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.723 × 10⁹⁹(100-digit number)
27233809287607858088…76170499505476352001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.446 × 10⁹⁹(100-digit number)
54467618575215716176…52340999010952704001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.089 × 10¹⁰⁰(101-digit number)
10893523715043143235…04681998021905408001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.178 × 10¹⁰⁰(101-digit number)
21787047430086286470…09363996043810816001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.357 × 10¹⁰⁰(101-digit number)
43574094860172572941…18727992087621632001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.714 × 10¹⁰⁰(101-digit number)
87148189720345145882…37455984175243264001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.742 × 10¹⁰¹(102-digit number)
17429637944069029176…74911968350486528001
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:57,597,706 XPM·at block #6,794,209 · updates every 60s
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