Block #341,137

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/3/2014, 6:47:45 AM · Difficulty 10.1310 · 6,462,227 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
feb940c1680cf6f73cc7769b91fc3b4f75612ce5c181fecda6e61068fcc30e40

Height

#341,137

Difficulty

10.131009

Transactions

20

Size

46.94 KB

Version

2

Bits

0a2189d0

Nonce

78,178

Timestamp

1/3/2014, 6:47:45 AM

Confirmations

6,462,227

Merkle Root

6b6a6a0576dea39d526b396b165d2a9506e1b4157a27fa5801bc87db70c066ca
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.

5.126 × 10⁹⁶(97-digit number)
51265121469634455691…93044210224558839041
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
5.126 × 10⁹⁶(97-digit number)
51265121469634455691…93044210224558839041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.025 × 10⁹⁷(98-digit number)
10253024293926891138…86088420449117678081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.050 × 10⁹⁷(98-digit number)
20506048587853782276…72176840898235356161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.101 × 10⁹⁷(98-digit number)
41012097175707564553…44353681796470712321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.202 × 10⁹⁷(98-digit number)
82024194351415129106…88707363592941424641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.640 × 10⁹⁸(99-digit number)
16404838870283025821…77414727185882849281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.280 × 10⁹⁸(99-digit number)
32809677740566051642…54829454371765698561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.561 × 10⁹⁸(99-digit number)
65619355481132103285…09658908743531397121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.312 × 10⁹⁹(100-digit number)
13123871096226420657…19317817487062794241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.624 × 10⁹⁹(100-digit number)
26247742192452841314…38635634974125588481
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:57,670,948 XPM·at block #6,803,363 · updates every 60s
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