Block #314,587

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/16/2013, 1:19:06 AM · Difficulty 10.0679 · 6,484,745 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
ced2bc5a6613baf58c9b4d3c65bec9bacc63aac72910e1e0f2d1db059b61e8af

Height

#314,587

Difficulty

10.067869

Transactions

12

Size

3.06 KB

Version

2

Bits

0a115fe1

Nonce

147,784

Timestamp

12/16/2013, 1:19:06 AM

Confirmations

6,484,745

Merkle Root

278c0ff7e17bb92afb7260d616125efd05553e7a03518d5bf96b2b4c8ce5d9d3
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.

9.257 × 10⁹⁷(98-digit number)
92572981728425468188…98004286239447956161
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
9.257 × 10⁹⁷(98-digit number)
92572981728425468188…98004286239447956161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.851 × 10⁹⁸(99-digit number)
18514596345685093637…96008572478895912321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.702 × 10⁹⁸(99-digit number)
37029192691370187275…92017144957791824641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.405 × 10⁹⁸(99-digit number)
74058385382740374550…84034289915583649281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.481 × 10⁹⁹(100-digit number)
14811677076548074910…68068579831167298561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.962 × 10⁹⁹(100-digit number)
29623354153096149820…36137159662334597121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.924 × 10⁹⁹(100-digit number)
59246708306192299640…72274319324669194241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.184 × 10¹⁰⁰(101-digit number)
11849341661238459928…44548638649338388481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.369 × 10¹⁰⁰(101-digit number)
23698683322476919856…89097277298676776961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.739 × 10¹⁰⁰(101-digit number)
47397366644953839712…78194554597353553921
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:57,638,706 XPM·at block #6,799,331 · updates every 60s
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