Block #376,432

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 1/26/2014, 10:04:55 AM · Difficulty 10.4231 · 6,450,237 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
188ec7910d5548ea37eec535c48296f596e8997b9a745e7ff00888ad718e06bb

Height

#376,432

Difficulty

10.423145

Transactions

3

Size

2.75 KB

Version

2

Bits

0a6c5334

Nonce

237,441

Timestamp

1/26/2014, 10:04:55 AM

Confirmations

6,450,237

Merkle Root

96cd6e02d812878037acbaa10cc9d3a4d481db78c4462bf9b3d590dafa0f656d
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.

8.794 × 10⁹⁶(97-digit number)
87941233400901760729…08651139865512401921
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
8.794 × 10⁹⁶(97-digit number)
87941233400901760729…08651139865512401921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.758 × 10⁹⁷(98-digit number)
17588246680180352145…17302279731024803841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.517 × 10⁹⁷(98-digit number)
35176493360360704291…34604559462049607681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
7.035 × 10⁹⁷(98-digit number)
70352986720721408583…69209118924099215361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.407 × 10⁹⁸(99-digit number)
14070597344144281716…38418237848198430721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.814 × 10⁹⁸(99-digit number)
28141194688288563433…76836475696396861441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.628 × 10⁹⁸(99-digit number)
56282389376577126866…53672951392793722881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.125 × 10⁹⁹(100-digit number)
11256477875315425373…07345902785587445761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.251 × 10⁹⁹(100-digit number)
22512955750630850746…14691805571174891521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.502 × 10⁹⁹(100-digit number)
45025911501261701493…29383611142349783041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
9.005 × 10⁹⁹(100-digit number)
90051823002523402986…58767222284699566081
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,857,499 XPM·at block #6,826,668 · 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.
Privacy Policy·

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