Block #566,748

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/29/2014, 3:35:40 AM · Difficulty 10.9660 · 6,244,412 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
956c47a261b568044425b1d04c5728caf4e2456b48e0912ba26750b2a4389b55

Height

#566,748

Difficulty

10.965957

Transactions

13

Size

12.13 KB

Version

2

Bits

0af748f7

Nonce

244,560,831

Timestamp

5/29/2014, 3:35:40 AM

Confirmations

6,244,412

Merkle Root

5f71a2729409454fcc4fba86122af998e27e6bfb770f39f6e649e2b156fc427d
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.

5.491 × 10⁹⁸(99-digit number)
54912742530825840543…84596589789877740801
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
5.491 × 10⁹⁸(99-digit number)
54912742530825840543…84596589789877740801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.098 × 10⁹⁹(100-digit number)
10982548506165168108…69193179579755481601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.196 × 10⁹⁹(100-digit number)
21965097012330336217…38386359159510963201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.393 × 10⁹⁹(100-digit number)
43930194024660672434…76772718319021926401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.786 × 10⁹⁹(100-digit number)
87860388049321344869…53545436638043852801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.757 × 10¹⁰⁰(101-digit number)
17572077609864268973…07090873276087705601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.514 × 10¹⁰⁰(101-digit number)
35144155219728537947…14181746552175411201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.028 × 10¹⁰⁰(101-digit number)
70288310439457075895…28363493104350822401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.405 × 10¹⁰¹(102-digit number)
14057662087891415179…56726986208701644801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.811 × 10¹⁰¹(102-digit number)
28115324175782830358…13453972417403289601
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:57,733,392 XPM·at block #6,811,159 · updates every 60s
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