Block #379,211

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/28/2014, 9:23:04 AM · Difficulty 10.4170 · 6,431,493 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
2a6926810cba46616537b28411aff1576c662183205d6e1341abd60c3a38c073

Height

#379,211

Difficulty

10.417004

Transactions

8

Size

1.89 KB

Version

2

Bits

0a6ac0c6

Nonce

13,321

Timestamp

1/28/2014, 9:23:04 AM

Confirmations

6,431,493

Merkle Root

d6629f24179ee83069e0cdd1f5fbb2030e7e185044c9da3f125a9ed825498964
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.

3.693 × 10⁹⁷(98-digit number)
36930904849841063504…70064771636583236001
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
3.693 × 10⁹⁷(98-digit number)
36930904849841063504…70064771636583236001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
7.386 × 10⁹⁷(98-digit number)
73861809699682127008…40129543273166472001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.477 × 10⁹⁸(99-digit number)
14772361939936425401…80259086546332944001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.954 × 10⁹⁸(99-digit number)
29544723879872850803…60518173092665888001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.908 × 10⁹⁸(99-digit number)
59089447759745701606…21036346185331776001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.181 × 10⁹⁹(100-digit number)
11817889551949140321…42072692370663552001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.363 × 10⁹⁹(100-digit number)
23635779103898280642…84145384741327104001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.727 × 10⁹⁹(100-digit number)
47271558207796561285…68290769482654208001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
9.454 × 10⁹⁹(100-digit number)
94543116415593122570…36581538965308416001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.890 × 10¹⁰⁰(101-digit number)
18908623283118624514…73163077930616832001
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:57,729,726 XPM·at block #6,810,703 · updates every 60s
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