Block #316,483

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 12/17/2013, 2:36:46 AM · Difficulty 10.1354 · 6,497,826 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a2faeece93fed4de0a53b4f5f4c3961ffaae67bc3a04c321201ea633e13c5aef

Height

#316,483

Difficulty

10.135368

Transactions

16

Size

4.86 KB

Version

2

Bits

0a22a77c

Nonce

19,765

Timestamp

12/17/2013, 2:36:46 AM

Confirmations

6,497,826

Merkle Root

e729303717d4b7a0a805df3c4056167017977922d382d83fe9c98a982f97d4f8
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.

2.699 × 10⁹⁷(98-digit number)
26992168082919056743…36788873716244607841
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
2.699 × 10⁹⁷(98-digit number)
26992168082919056743…36788873716244607841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.398 × 10⁹⁷(98-digit number)
53984336165838113487…73577747432489215681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.079 × 10⁹⁸(99-digit number)
10796867233167622697…47155494864978431361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.159 × 10⁹⁸(99-digit number)
21593734466335245395…94310989729956862721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.318 × 10⁹⁸(99-digit number)
43187468932670490790…88621979459913725441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.637 × 10⁹⁸(99-digit number)
86374937865340981580…77243958919827450881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.727 × 10⁹⁹(100-digit number)
17274987573068196316…54487917839654901761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.454 × 10⁹⁹(100-digit number)
34549975146136392632…08975835679309803521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
6.909 × 10⁹⁹(100-digit number)
69099950292272785264…17951671358619607041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.381 × 10¹⁰⁰(101-digit number)
13819990058454557052…35903342717239214081
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:57,758,534 XPM·at block #6,814,308 · 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