Block #430,163

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/5/2014, 7:58:45 AM · Difficulty 10.3403 · 6,363,407 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
1e3ad5b52b10a685266dd948a5abb121b8e1dca800aca83e69bb89a246ab6a42

Height

#430,163

Difficulty

10.340324

Transactions

12

Size

3.02 KB

Version

2

Bits

0a571f75

Nonce

21,459

Timestamp

3/5/2014, 7:58:45 AM

Confirmations

6,363,407

Merkle Root

9cdddbce28d04479a5c8ebb7fa37a9c88a33f4cf9afd017915afd27b4e417182
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.

2.326 × 10¹⁰⁰(101-digit number)
23264467156845872124…85256295032816601601
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
2.326 × 10¹⁰⁰(101-digit number)
23264467156845872124…85256295032816601601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.652 × 10¹⁰⁰(101-digit number)
46528934313691744248…70512590065633203201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
9.305 × 10¹⁰⁰(101-digit number)
93057868627383488496…41025180131266406401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.861 × 10¹⁰¹(102-digit number)
18611573725476697699…82050360262532812801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.722 × 10¹⁰¹(102-digit number)
37223147450953395398…64100720525065625601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
7.444 × 10¹⁰¹(102-digit number)
74446294901906790797…28201441050131251201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.488 × 10¹⁰²(103-digit number)
14889258980381358159…56402882100262502401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.977 × 10¹⁰²(103-digit number)
29778517960762716318…12805764200525004801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.955 × 10¹⁰²(103-digit number)
59557035921525432637…25611528401050009601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.191 × 10¹⁰³(104-digit number)
11911407184305086527…51223056802100019201
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:57,592,556 XPM·at block #6,793,569 · updates every 60s
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