Block #549,063

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 5/17/2014, 8:54:05 AM · Difficulty 10.9601 · 6,245,645 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
c01637e92c8a9037a20a1be01fffb64845c5d3725a78e4a00b6fd84c37c76b5b

Height

#549,063

Difficulty

10.960083

Transactions

6

Size

1.30 KB

Version

2

Bits

0af5c7ff

Nonce

96,542,192

Timestamp

5/17/2014, 8:54:05 AM

Confirmations

6,245,645

Merkle Root

38fadf2a659178f6dcf38ffa15937e3224c4656e233c25044fb750ce6d787f84
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.

8.141 × 10⁹⁸(99-digit number)
81414917789770676133…08480128154680798721
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
8.141 × 10⁹⁸(99-digit number)
81414917789770676133…08480128154680798721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.628 × 10⁹⁹(100-digit number)
16282983557954135226…16960256309361597441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.256 × 10⁹⁹(100-digit number)
32565967115908270453…33920512618723194881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.513 × 10⁹⁹(100-digit number)
65131934231816540906…67841025237446389761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.302 × 10¹⁰⁰(101-digit number)
13026386846363308181…35682050474892779521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.605 × 10¹⁰⁰(101-digit number)
26052773692726616362…71364100949785559041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.210 × 10¹⁰⁰(101-digit number)
52105547385453232725…42728201899571118081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.042 × 10¹⁰¹(102-digit number)
10421109477090646545…85456403799142236161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.084 × 10¹⁰¹(102-digit number)
20842218954181293090…70912807598284472321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.168 × 10¹⁰¹(102-digit number)
41684437908362586180…41825615196568944641
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:57,601,711 XPM·at block #6,794,707 · updates every 60s
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