Block #441,182

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/12/2014, 11:07:00 PM · Difficulty 10.3506 · 6,364,701 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
8769e20b2702203f2cd9bd9eaea27f3a9285a0e56080e532db7786f0f8d1ee2a

Height

#441,182

Difficulty

10.350605

Transactions

4

Size

2.13 KB

Version

2

Bits

0a59c147

Nonce

2,402

Timestamp

3/12/2014, 11:07:00 PM

Confirmations

6,364,701

Merkle Root

ca68f23425cacb875fc9058044d9a2d9d87a290b8a3968cf2efa246608e9fd75
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.

8.797 × 10⁹²(93-digit number)
87974025049905560870…35038624895184473761
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
8.797 × 10⁹²(93-digit number)
87974025049905560870…35038624895184473761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.759 × 10⁹³(94-digit number)
17594805009981112174…70077249790368947521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.518 × 10⁹³(94-digit number)
35189610019962224348…40154499580737895041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.037 × 10⁹³(94-digit number)
70379220039924448696…80308999161475790081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.407 × 10⁹⁴(95-digit number)
14075844007984889739…60617998322951580161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.815 × 10⁹⁴(95-digit number)
28151688015969779478…21235996645903160321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.630 × 10⁹⁴(95-digit number)
56303376031939558957…42471993291806320641
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.126 × 10⁹⁵(96-digit number)
11260675206387911791…84943986583612641281
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.252 × 10⁹⁵(96-digit number)
22521350412775823582…69887973167225282561
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.504 × 10⁹⁵(96-digit number)
45042700825551647165…39775946334450565121
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:57,691,149 XPM·at block #6,805,882 · updates every 60s
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