Block #486,319

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/11/2014, 12:59:15 PM · Difficulty 10.6237 · 6,329,747 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cdd749a6686fc1e3975063394d908dd3bc1c41d795057b6db039a2c54ff16179

Height

#486,319

Difficulty

10.623712

Transactions

10

Size

2.63 KB

Version

2

Bits

0a9fab9b

Nonce

37,692

Timestamp

4/11/2014, 12:59:15 PM

Confirmations

6,329,747

Merkle Root

4618ec2ff9932dba270b21819bb44446a87580496fd70b521bb6dc09ff5ee89d
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.

3.450 × 10⁹⁵(96-digit number)
34503734275225649085…60109935225774911721
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
3.450 × 10⁹⁵(96-digit number)
34503734275225649085…60109935225774911721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.900 × 10⁹⁵(96-digit number)
69007468550451298171…20219870451549823441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.380 × 10⁹⁶(97-digit number)
13801493710090259634…40439740903099646881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.760 × 10⁹⁶(97-digit number)
27602987420180519268…80879481806199293761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
5.520 × 10⁹⁶(97-digit number)
55205974840361038536…61758963612398587521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.104 × 10⁹⁷(98-digit number)
11041194968072207707…23517927224797175041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
2.208 × 10⁹⁷(98-digit number)
22082389936144415414…47035854449594350081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
4.416 × 10⁹⁷(98-digit number)
44164779872288830829…94071708899188700161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
8.832 × 10⁹⁷(98-digit number)
88329559744577661659…88143417798377400321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.766 × 10⁹⁸(99-digit number)
17665911948915532331…76286835596754800641
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:57,772,645 XPM·at block #6,816,065 · 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