Block #379,549

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/28/2014, 2:40:37 PM · Difficulty 10.4194 · 6,425,628 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cc76745b082993996cdf84762f6865c868862a5c37d0aab00e3c605269f9db03

Height

#379,549

Difficulty

10.419381

Transactions

6

Size

1.25 KB

Version

2

Bits

0a6b5c86

Nonce

213,171

Timestamp

1/28/2014, 2:40:37 PM

Confirmations

6,425,628

Merkle Root

c8003f41c408d9394d3d7db0affa469c108fc2bad8fbd5244a86e5af5963681b
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.

5.903 × 10⁹⁶(97-digit number)
59035495046661619560…67887626151838055201
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
5.903 × 10⁹⁶(97-digit number)
59035495046661619560…67887626151838055201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.180 × 10⁹⁷(98-digit number)
11807099009332323912…35775252303676110401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.361 × 10⁹⁷(98-digit number)
23614198018664647824…71550504607352220801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.722 × 10⁹⁷(98-digit number)
47228396037329295648…43101009214704441601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
9.445 × 10⁹⁷(98-digit number)
94456792074658591296…86202018429408883201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.889 × 10⁹⁸(99-digit number)
18891358414931718259…72404036858817766401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.778 × 10⁹⁸(99-digit number)
37782716829863436518…44808073717635532801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
7.556 × 10⁹⁸(99-digit number)
75565433659726873037…89616147435271065601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.511 × 10⁹⁹(100-digit number)
15113086731945374607…79232294870542131201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.022 × 10⁹⁹(100-digit number)
30226173463890749214…58464589741084262401
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:57,685,485 XPM·at block #6,805,176 · updates every 60s
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