Block #508,892

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/24/2014, 4:55:37 PM · Difficulty 10.8190 · 6,295,304 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
67f6a15120ae95bf15a1b9452b29dc7a0fead7fb0957225be6024e1a73ff38eb

Height

#508,892

Difficulty

10.818980

Transactions

4

Size

2.46 KB

Version

2

Bits

0ad1a8b1

Nonce

1,282,626

Timestamp

4/24/2014, 4:55:37 PM

Confirmations

6,295,304

Merkle Root

70f23de4b764d125d6a62a0e6f81cd4886ed1ed3cec25889770560a412789780
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.

1.017 × 10⁹⁹(100-digit number)
10177317506326519134…50550727259867776321
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
1.017 × 10⁹⁹(100-digit number)
10177317506326519134…50550727259867776321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.035 × 10⁹⁹(100-digit number)
20354635012653038269…01101454519735552641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.070 × 10⁹⁹(100-digit number)
40709270025306076538…02202909039471105281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.141 × 10⁹⁹(100-digit number)
81418540050612153077…04405818078942210561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.628 × 10¹⁰⁰(101-digit number)
16283708010122430615…08811636157884421121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.256 × 10¹⁰⁰(101-digit number)
32567416020244861231…17623272315768842241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.513 × 10¹⁰⁰(101-digit number)
65134832040489722462…35246544631537684481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.302 × 10¹⁰¹(102-digit number)
13026966408097944492…70493089263075368961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.605 × 10¹⁰¹(102-digit number)
26053932816195888984…40986178526150737921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.210 × 10¹⁰¹(102-digit number)
52107865632391777969…81972357052301475841
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:57,677,615 XPM·at block #6,804,195 · updates every 60s
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