Block #571,780

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 6/1/2014, 4:40:00 PM · Difficulty 10.9656 · 6,223,672 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
40576385b34456ef791f81fe1054cd68d3acd0d476135b716b515faa710dec57

Height

#571,780

Difficulty

10.965633

Transactions

8

Size

1.89 KB

Version

2

Bits

0af733bf

Nonce

103,737,667

Timestamp

6/1/2014, 4:40:00 PM

Confirmations

6,223,672

Merkle Root

d653821f17c8db3c44c71c916a5b60f5dd88886491c4f8d3e6e943dbfd6bd8f3
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.

1.099 × 10¹⁰⁰(101-digit number)
10991140787225188576…21463870583569264641
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
1.099 × 10¹⁰⁰(101-digit number)
10991140787225188576…21463870583569264641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.198 × 10¹⁰⁰(101-digit number)
21982281574450377152…42927741167138529281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.396 × 10¹⁰⁰(101-digit number)
43964563148900754305…85855482334277058561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
8.792 × 10¹⁰⁰(101-digit number)
87929126297801508610…71710964668554117121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.758 × 10¹⁰¹(102-digit number)
17585825259560301722…43421929337108234241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.517 × 10¹⁰¹(102-digit number)
35171650519120603444…86843858674216468481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.034 × 10¹⁰¹(102-digit number)
70343301038241206888…73687717348432936961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.406 × 10¹⁰²(103-digit number)
14068660207648241377…47375434696865873921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.813 × 10¹⁰²(103-digit number)
28137320415296482755…94750869393731747841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.627 × 10¹⁰²(103-digit number)
56274640830592965510…89501738787463495681
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:57,607,674 XPM·at block #6,795,451 · updates every 60s
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