Block #568,737

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/30/2014, 4:11:54 PM · Difficulty 10.9646 · 6,240,561 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
bf2d02061a7437e28214c2109f188dc6b64d2224bd6e619644f6ca8ce0118625

Height

#568,737

Difficulty

10.964601

Transactions

7

Size

2.80 KB

Version

2

Bits

0af6f017

Nonce

103,793

Timestamp

5/30/2014, 4:11:54 PM

Confirmations

6,240,561

Merkle Root

349e5fe5b4762478bb03c9eb77d98f726d5d32b02d4cc3a6d92980d01ed2f005
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.

1.008 × 10⁹⁷(98-digit number)
10083855962457883075…48352422654252103681
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
1.008 × 10⁹⁷(98-digit number)
10083855962457883075…48352422654252103681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.016 × 10⁹⁷(98-digit number)
20167711924915766150…96704845308504207361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.033 × 10⁹⁷(98-digit number)
40335423849831532301…93409690617008414721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.067 × 10⁹⁷(98-digit number)
80670847699663064602…86819381234016829441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.613 × 10⁹⁸(99-digit number)
16134169539932612920…73638762468033658881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.226 × 10⁹⁸(99-digit number)
32268339079865225841…47277524936067317761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
6.453 × 10⁹⁸(99-digit number)
64536678159730451682…94555049872134635521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.290 × 10⁹⁹(100-digit number)
12907335631946090336…89110099744269271041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.581 × 10⁹⁹(100-digit number)
25814671263892180672…78220199488538542081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.162 × 10⁹⁹(100-digit number)
51629342527784361345…56440398977077084161
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:57,718,454 XPM·at block #6,809,297 · updates every 60s
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