Block #526,825

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/5/2014, 3:21:56 PM · Difficulty 10.8834 · 6,278,190 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
6af1a8d8437c4fc6fe41ea6db973e150652ec60ad3d3d142d95d0c8ab5dc20ee

Height

#526,825

Difficulty

10.883444

Transactions

9

Size

2.11 KB

Version

2

Bits

0ae22967

Nonce

98,406,362

Timestamp

5/5/2014, 3:21:56 PM

Confirmations

6,278,190

Merkle Root

9fa7b8b547df4fdcf5d4b9190e7b2501ec1ae5d1a1f00ece9bf20b08bf76f3ad
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.

5.883 × 10⁹⁸(99-digit number)
58834560089816217276…50569945733895858201
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
5.883 × 10⁹⁸(99-digit number)
58834560089816217276…50569945733895858201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.176 × 10⁹⁹(100-digit number)
11766912017963243455…01139891467791716401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.353 × 10⁹⁹(100-digit number)
23533824035926486910…02279782935583432801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.706 × 10⁹⁹(100-digit number)
47067648071852973820…04559565871166865601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.413 × 10⁹⁹(100-digit number)
94135296143705947641…09119131742333731201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.882 × 10¹⁰⁰(101-digit number)
18827059228741189528…18238263484667462401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.765 × 10¹⁰⁰(101-digit number)
37654118457482379056…36476526969334924801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.530 × 10¹⁰⁰(101-digit number)
75308236914964758113…72953053938669849601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.506 × 10¹⁰¹(102-digit number)
15061647382992951622…45906107877339699201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.012 × 10¹⁰¹(102-digit number)
30123294765985903245…91812215754679398401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
6.024 × 10¹⁰¹(102-digit number)
60246589531971806490…83624431509358796801
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,684,190 XPM·at block #6,805,014 · updates every 60s
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