Block #568,677

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 5/30/2014, 3:18:23 PM · Difficulty 10.9646 · 6,227,173 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
bf96be886e24f69c8b8b89817e8ae9f83a79bd1133d20ca9e5d0f7e87eef4030

Height

#568,677

Difficulty

10.964551

Transactions

5

Size

2.24 KB

Version

2

Bits

0af6eccf

Nonce

219,992,211

Timestamp

5/30/2014, 3:18:23 PM

Confirmations

6,227,173

Merkle Root

5bf10dede07bdc7f46614c6152030a5c8a7c4d9c4566178285fccd044b650a81
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.

2.012 × 10⁹⁸(99-digit number)
20124172447837253500…52173741925787620641
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
2.012 × 10⁹⁸(99-digit number)
20124172447837253500…52173741925787620641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.024 × 10⁹⁸(99-digit number)
40248344895674507000…04347483851575241281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
8.049 × 10⁹⁸(99-digit number)
80496689791349014001…08694967703150482561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.609 × 10⁹⁹(100-digit number)
16099337958269802800…17389935406300965121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.219 × 10⁹⁹(100-digit number)
32198675916539605600…34779870812601930241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.439 × 10⁹⁹(100-digit number)
64397351833079211201…69559741625203860481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.287 × 10¹⁰⁰(101-digit number)
12879470366615842240…39119483250407720961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.575 × 10¹⁰⁰(101-digit number)
25758940733231684480…78238966500815441921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.151 × 10¹⁰⁰(101-digit number)
51517881466463368960…56477933001630883841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.030 × 10¹⁰¹(102-digit number)
10303576293292673792…12955866003261767681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.060 × 10¹⁰¹(102-digit number)
20607152586585347584…25911732006523535361
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:57,610,885 XPM·at block #6,795,849 · updates every 60s
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