Block #430,160

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/5/2014, 8:01:17 AM · Difficulty 10.3407 · 6,383,857 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
67afe9b7cd5213082f2ab8fc1b62916033fef736d9473d635aee421a19e6f9be

Height

#430,160

Difficulty

10.340663

Transactions

6

Size

1.93 KB

Version

2

Bits

0a5735b1

Nonce

65,008

Timestamp

3/5/2014, 8:01:17 AM

Confirmations

6,383,857

Merkle Root

ca90ab10d764ff7a5164cfbb536f78e6c10f9da316f4b4d35aeefe6e65b8ef7f
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.

5.579 × 10¹⁰¹(102-digit number)
55798491622946769898…91091803080884275841
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
5.579 × 10¹⁰¹(102-digit number)
55798491622946769898…91091803080884275841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.115 × 10¹⁰²(103-digit number)
11159698324589353979…82183606161768551681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.231 × 10¹⁰²(103-digit number)
22319396649178707959…64367212323537103361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.463 × 10¹⁰²(103-digit number)
44638793298357415918…28734424647074206721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.927 × 10¹⁰²(103-digit number)
89277586596714831837…57468849294148413441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.785 × 10¹⁰³(104-digit number)
17855517319342966367…14937698588296826881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.571 × 10¹⁰³(104-digit number)
35711034638685932735…29875397176593653761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.142 × 10¹⁰³(104-digit number)
71422069277371865470…59750794353187307521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.428 × 10¹⁰⁴(105-digit number)
14284413855474373094…19501588706374615041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.856 × 10¹⁰⁴(105-digit number)
28568827710948746188…39003177412749230081
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:57,756,220 XPM·at block #6,814,016 · updates every 60s
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