Block #310,794

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/14/2013, 6:05:43 AM · Difficulty 9.9953 · 6,483,648 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
82967a0b407aa913a6fe6c01207c3937f1740be2f90d3537c302014c62f5dd17

Height

#310,794

Difficulty

9.995291

Transactions

8

Size

2.17 KB

Version

2

Bits

09fecb6b

Nonce

140,291

Timestamp

12/14/2013, 6:05:43 AM

Confirmations

6,483,648

Merkle Root

8e51689d76ee3024e2fdc38ee794c5136379acde090ad713578435ed5eb8c611
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.

1.417 × 10⁸⁸(89-digit number)
14171151330647956393…78968085204766511241
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
1.417 × 10⁸⁸(89-digit number)
14171151330647956393…78968085204766511241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.834 × 10⁸⁸(89-digit number)
28342302661295912786…57936170409533022481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
5.668 × 10⁸⁸(89-digit number)
56684605322591825572…15872340819066044961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.133 × 10⁸⁹(90-digit number)
11336921064518365114…31744681638132089921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
2.267 × 10⁸⁹(90-digit number)
22673842129036730228…63489363276264179841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
4.534 × 10⁸⁹(90-digit number)
45347684258073460457…26978726552528359681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
9.069 × 10⁸⁹(90-digit number)
90695368516146920915…53957453105056719361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.813 × 10⁹⁰(91-digit number)
18139073703229384183…07914906210113438721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.627 × 10⁹⁰(91-digit number)
36278147406458768366…15829812420226877441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
7.255 × 10⁹⁰(91-digit number)
72556294812917536732…31659624840453754881
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:57,599,574 XPM·at block #6,794,441 · updates every 60s
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