Block #314,708

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 3:03:20 AM · Difficulty 10.0711 · 6,481,104 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7ed3e57e806bbeb1f5a80a957bca48984cc5ba896d4014c8d3884cb159554429

Height

#314,708

Difficulty

10.071113

Transactions

16

Size

3.47 KB

Version

2

Bits

0a12347d

Nonce

51,123

Timestamp

12/16/2013, 3:03:20 AM

Confirmations

6,481,104

Merkle Root

e0feaa29a291b224e1019cccd5fed7a68a3876aee37f07fa0a5be556423a2477
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.

9.237 × 10⁹³(94-digit number)
92375895641507751646…49131726674501004001
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
9.237 × 10⁹³(94-digit number)
92375895641507751646…49131726674501004001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.847 × 10⁹⁴(95-digit number)
18475179128301550329…98263453349002008001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.695 × 10⁹⁴(95-digit number)
36950358256603100658…96526906698004016001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.390 × 10⁹⁴(95-digit number)
73900716513206201317…93053813396008032001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.478 × 10⁹⁵(96-digit number)
14780143302641240263…86107626792016064001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.956 × 10⁹⁵(96-digit number)
29560286605282480526…72215253584032128001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.912 × 10⁹⁵(96-digit number)
59120573210564961053…44430507168064256001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.182 × 10⁹⁶(97-digit number)
11824114642112992210…88861014336128512001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.364 × 10⁹⁶(97-digit number)
23648229284225984421…77722028672257024001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.729 × 10⁹⁶(97-digit number)
47296458568451968843…55444057344514048001
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:57,610,576 XPM·at block #6,795,811 · updates every 60s
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