Block #481,594

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 4/8/2014, 11:53:07 PM · Difficulty 10.5344 · 6,328,730 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
3853df24c71941d1cb5b26b340206896c2d60d26034b6dedfe92a0d5f38f6b2e

Height

#481,594

Difficulty

10.534390

Transactions

3

Size

2.52 KB

Version

2

Bits

0a88cdc4

Nonce

2,074,901,457

Timestamp

4/8/2014, 11:53:07 PM

Confirmations

6,328,730

Merkle Root

4bd7747d5bd47bee5aba23a2db48b59d675633216df6d405fd7e116446ddd4cf
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.

1.215 × 10⁹⁴(95-digit number)
12151623509067251311…10231950600364939101
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
1.215 × 10⁹⁴(95-digit number)
12151623509067251311…10231950600364939101
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
2.430 × 10⁹⁴(95-digit number)
24303247018134502622…20463901200729878201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
4.860 × 10⁹⁴(95-digit number)
48606494036269005244…40927802401459756401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
9.721 × 10⁹⁴(95-digit number)
97212988072538010489…81855604802919512801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.944 × 10⁹⁵(96-digit number)
19442597614507602097…63711209605839025601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
3.888 × 10⁹⁵(96-digit number)
38885195229015204195…27422419211678051201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
7.777 × 10⁹⁵(96-digit number)
77770390458030408391…54844838423356102401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.555 × 10⁹⁶(97-digit number)
15554078091606081678…09689676846712204801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
3.110 × 10⁹⁶(97-digit number)
31108156183212163356…19379353693424409601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
6.221 × 10⁹⁶(97-digit number)
62216312366424326713…38758707386848819201
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:57,726,671 XPM·at block #6,810,323 · 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