Block #527,944

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/6/2014, 9:02:37 AM · Difficulty 10.8848 · 6,275,656 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
afd1cbafd4eba0a713c0ec8e4190c24fd4bc113564d79a3c715f56f41f3f0996

Height

#527,944

Difficulty

10.884847

Transactions

13

Size

2.82 KB

Version

2

Bits

0ae2855a

Nonce

1,928,722

Timestamp

5/6/2014, 9:02:37 AM

Confirmations

6,275,656

Merkle Root

4f821125b3726a47a914d007ecb98f7af939b037478af32e2344ca4a69c9f453
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.

1.149 × 10¹⁰¹(102-digit number)
11494784367720055468…92711203868043161601
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
1.149 × 10¹⁰¹(102-digit number)
11494784367720055468…92711203868043161601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.298 × 10¹⁰¹(102-digit number)
22989568735440110936…85422407736086323201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.597 × 10¹⁰¹(102-digit number)
45979137470880221873…70844815472172646401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.195 × 10¹⁰¹(102-digit number)
91958274941760443746…41689630944345292801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.839 × 10¹⁰²(103-digit number)
18391654988352088749…83379261888690585601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.678 × 10¹⁰²(103-digit number)
36783309976704177498…66758523777381171201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.356 × 10¹⁰²(103-digit number)
73566619953408354997…33517047554762342401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.471 × 10¹⁰³(104-digit number)
14713323990681670999…67034095109524684801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.942 × 10¹⁰³(104-digit number)
29426647981363341998…34068190219049369601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.885 × 10¹⁰³(104-digit number)
58853295962726683997…68136380438098739201
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:57,672,838 XPM·at block #6,803,599 · updates every 60s
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