Block #2,714,688

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 6/21/2018, 8:18:48 AM · Difficulty 11.6104 · 4,123,014 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
f83a76e161f46940b5ba669ef67d1a66da38c094d54a40d8dcc31917d3ade42c

Height

#2,714,688

Difficulty

11.610384

Transactions

2

Size

608 B

Version

2

Bits

0b9c4227

Nonce

987,467,419

Timestamp

6/21/2018, 8:18:48 AM

Confirmations

4,123,014

Merkle Root

c8cb44db9c86633ef34e9660acb8b5ed1edd758bc169e387e71a32703d490e05
Transactions (2)
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.

7.975 × 10⁹³(94-digit number)
79753483966337166432…12783521926560367361
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
7.975 × 10⁹³(94-digit number)
79753483966337166432…12783521926560367361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.595 × 10⁹⁴(95-digit number)
15950696793267433286…25567043853120734721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
3.190 × 10⁹⁴(95-digit number)
31901393586534866572…51134087706241469441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
6.380 × 10⁹⁴(95-digit number)
63802787173069733145…02268175412482938881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
1.276 × 10⁹⁵(96-digit number)
12760557434613946629…04536350824965877761
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
2.552 × 10⁹⁵(96-digit number)
25521114869227893258…09072701649931755521
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
5.104 × 10⁹⁵(96-digit number)
51042229738455786516…18145403299863511041
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
1.020 × 10⁹⁶(97-digit number)
10208445947691157303…36290806599727022081
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
2.041 × 10⁹⁶(97-digit number)
20416891895382314606…72581613199454044161
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
4.083 × 10⁹⁶(97-digit number)
40833783790764629213…45163226398908088321
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
8.166 × 10⁹⁶(97-digit number)
81667567581529258426…90326452797816176641
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,945,944 XPM·at block #6,837,701 · 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