Block #568,298

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/30/2014, 7:51:35 AM · Difficulty 10.9650 · 6,237,756 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
06443bba09b8af45f45e45b8c60de1122e35927f1fcdd0775e09d705fd0d47b5

Height

#568,298

Difficulty

10.964999

Transactions

4

Size

1.01 KB

Version

2

Bits

0af70a32

Nonce

895,645,006

Timestamp

5/30/2014, 7:51:35 AM

Confirmations

6,237,756

Merkle Root

1abe098898669fa7d00cf4e7c440b3d333d564beedcec2a078246e210c072cea
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.

2.075 × 10⁹⁸(99-digit number)
20754658856592395881…23052910451058665601
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
2.075 × 10⁹⁸(99-digit number)
20754658856592395881…23052910451058665601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
4.150 × 10⁹⁸(99-digit number)
41509317713184791763…46105820902117331201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
8.301 × 10⁹⁸(99-digit number)
83018635426369583527…92211641804234662401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
1.660 × 10⁹⁹(100-digit number)
16603727085273916705…84423283608469324801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
3.320 × 10⁹⁹(100-digit number)
33207454170547833410…68846567216938649601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
6.641 × 10⁹⁹(100-digit number)
66414908341095666821…37693134433877299201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.328 × 10¹⁰⁰(101-digit number)
13282981668219133364…75386268867754598401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
2.656 × 10¹⁰⁰(101-digit number)
26565963336438266728…50772537735509196801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
5.313 × 10¹⁰⁰(101-digit number)
53131926672876533457…01545075471018393601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.062 × 10¹⁰¹(102-digit number)
10626385334575306691…03090150942036787201
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:57,692,515 XPM·at block #6,806,053 · updates every 60s
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