Block #443,595

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/14/2014, 3:58:19 PM · Difficulty 10.3474 · 6,366,457 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
89f61e9ccfc4725b54330ec32e8c2d427ad41442f67265a284adcb32d5635f0e

Height

#443,595

Difficulty

10.347426

Transactions

3

Size

14.81 KB

Version

2

Bits

0a58f0e4

Nonce

4,125,827

Timestamp

3/14/2014, 3:58:19 PM

Confirmations

6,366,457

Merkle Root

66d90155181bbe6464984c4ae67ee000f3d2c5ac63189f84cb8cef071826db1c
Transactions (3)
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.

3.457 × 10⁹⁶(97-digit number)
34573872808922016944…77272535253647882241
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
3.457 × 10⁹⁶(97-digit number)
34573872808922016944…77272535253647882241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.914 × 10⁹⁶(97-digit number)
69147745617844033889…54545070507295764481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.382 × 10⁹⁷(98-digit number)
13829549123568806777…09090141014591528961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.765 × 10⁹⁷(98-digit number)
27659098247137613555…18180282029183057921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.531 × 10⁹⁷(98-digit number)
55318196494275227111…36360564058366115841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.106 × 10⁹⁸(99-digit number)
11063639298855045422…72721128116732231681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.212 × 10⁹⁸(99-digit number)
22127278597710090844…45442256233464463361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.425 × 10⁹⁸(99-digit number)
44254557195420181688…90884512466928926721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.850 × 10⁹⁸(99-digit number)
88509114390840363377…81769024933857853441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.770 × 10⁹⁹(100-digit number)
17701822878168072675…63538049867715706881
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:57,724,489 XPM·at block #6,810,051 · updates every 60s
xpmprime.info is a work in progress. If you enjoy using this service you can support this project with a Primecoin donation.

Cookie Preferences

We use cookies to enhance your experience. Some are essential for the site to function, while others help us understand how you use the site.

·Privacy Policy