Block #332,641

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/28/2013, 5:15:34 AM · Difficulty 10.1680 · 6,469,944 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
4e9974523254aaadeed344a3869d0edc44b453a27e3a832b8dba75379aad153a

Height

#332,641

Difficulty

10.167960

Transactions

9

Size

3.44 KB

Version

2

Bits

0a2aff65

Nonce

82,383

Timestamp

12/28/2013, 5:15:34 AM

Confirmations

6,469,944

Merkle Root

523fc6aab34847aac49f73c9a6cf8b4877d22ee6eb91640711eb1992973b9944
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.

1.159 × 10⁹⁷(98-digit number)
11597466337395357699…73993293010097024001
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
1.159 × 10⁹⁷(98-digit number)
11597466337395357699…73993293010097024001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.319 × 10⁹⁷(98-digit number)
23194932674790715398…47986586020194048001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.638 × 10⁹⁷(98-digit number)
46389865349581430797…95973172040388096001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.277 × 10⁹⁷(98-digit number)
92779730699162861595…91946344080776192001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.855 × 10⁹⁸(99-digit number)
18555946139832572319…83892688161552384001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.711 × 10⁹⁸(99-digit number)
37111892279665144638…67785376323104768001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.422 × 10⁹⁸(99-digit number)
74223784559330289276…35570752646209536001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.484 × 10⁹⁹(100-digit number)
14844756911866057855…71141505292419072001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.968 × 10⁹⁹(100-digit number)
29689513823732115710…42283010584838144001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
5.937 × 10⁹⁹(100-digit number)
59379027647464231421…84566021169676288001
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:57,664,698 XPM·at block #6,802,584 · 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.