Block #377,457

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 1/27/2014, 3:37:53 AM · Difficulty 10.4195 · 6,433,635 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
5189e325e9cdbda3a8fbbba165d0ab1dec2ae24b630414ca59b38d208818839a

Height

#377,457

Difficulty

10.419496

Transactions

2

Size

839 B

Version

2

Bits

0a6b641b

Nonce

108,528

Timestamp

1/27/2014, 3:37:53 AM

Confirmations

6,433,635

Merkle Root

0c572241cbd25e850b83796530653929d5887d1d384e4b9a78e2b0e070cdc4fa
Transactions (2)
1 in → 1 out9.2100 XPM111 B
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.

7.608 × 10⁹⁸(99-digit number)
76084750610344778447…51892117749984618241
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
7.608 × 10⁹⁸(99-digit number)
76084750610344778447…51892117749984618241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.521 × 10⁹⁹(100-digit number)
15216950122068955689…03784235499969236481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.043 × 10⁹⁹(100-digit number)
30433900244137911378…07568470999938472961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.086 × 10⁹⁹(100-digit number)
60867800488275822757…15136941999876945921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.217 × 10¹⁰⁰(101-digit number)
12173560097655164551…30273883999753891841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.434 × 10¹⁰⁰(101-digit number)
24347120195310329103…60547767999507783681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
4.869 × 10¹⁰⁰(101-digit number)
48694240390620658206…21095535999015567361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
9.738 × 10¹⁰⁰(101-digit number)
97388480781241316412…42191071998031134721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.947 × 10¹⁰¹(102-digit number)
19477696156248263282…84382143996062269441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
3.895 × 10¹⁰¹(102-digit number)
38955392312496526564…68764287992124538881
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:57,732,843 XPM·at block #6,811,091 · 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