Block #562,534

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/26/2014, 4:05:20 AM · Difficulty 10.9663 · 6,230,273 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d4339f78ff01fedcf87aa62f285aeae1e31d6365acf16b42328bac3a9b94c71f

Height

#562,534

Difficulty

10.966341

Transactions

9

Size

2.25 KB

Version

2

Bits

0af76221

Nonce

7,404,260

Timestamp

5/26/2014, 4:05:20 AM

Confirmations

6,230,273

Merkle Root

ef7937a48e7e356c602b3e3947135e572793bb27f370cb38f6cb4e5a851864b7
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.

7.011 × 10⁹⁷(98-digit number)
70119588652070170116…21899136507709296401
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
7.011 × 10⁹⁷(98-digit number)
70119588652070170116…21899136507709296401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.402 × 10⁹⁸(99-digit number)
14023917730414034023…43798273015418592801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.804 × 10⁹⁸(99-digit number)
28047835460828068046…87596546030837185601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
5.609 × 10⁹⁸(99-digit number)
56095670921656136093…75193092061674371201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.121 × 10⁹⁹(100-digit number)
11219134184331227218…50386184123348742401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.243 × 10⁹⁹(100-digit number)
22438268368662454437…00772368246697484801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.487 × 10⁹⁹(100-digit number)
44876536737324908874…01544736493394969601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
8.975 × 10⁹⁹(100-digit number)
89753073474649817748…03089472986789939201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.795 × 10¹⁰⁰(101-digit number)
17950614694929963549…06178945973579878401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.590 × 10¹⁰⁰(101-digit number)
35901229389859927099…12357891947159756801
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:57,586,440 XPM·at block #6,792,806 · updates every 60s
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