Block #2,923,114

2CCLength 11★★★☆☆

Cunningham Chain of the Second Kind · Discovered 11/14/2018, 9:19:41 PM · Difficulty 11.3618 · 3,917,076 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
7ac2db1fb7ecaa41ec06dcfe03a77c6dcbfb33b20c3f2ecc72ae2763fe8cb4c3

Height

#2,923,114

Difficulty

11.361809

Transactions

4

Size

1.59 KB

Version

2

Bits

0b5c9f88

Nonce

350,341,787

Timestamp

11/14/2018, 9:19:41 PM

Confirmations

3,917,076

Merkle Root

030f6c1fdf415bcb495a33a070829af1fa7e684ef8b67327806981f57b48d6db
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.

2.813 × 10⁹⁵(96-digit number)
28135923724451780212…53010033526272345601
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
2.813 × 10⁹⁵(96-digit number)
28135923724451780212…53010033526272345601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.627 × 10⁹⁵(96-digit number)
56271847448903560425…06020067052544691201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.125 × 10⁹⁶(97-digit number)
11254369489780712085…12040134105089382401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.250 × 10⁹⁶(97-digit number)
22508738979561424170…24080268210178764801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.501 × 10⁹⁶(97-digit number)
45017477959122848340…48160536420357529601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.003 × 10⁹⁶(97-digit number)
90034955918245696681…96321072840715059201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.800 × 10⁹⁷(98-digit number)
18006991183649139336…92642145681430118401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.601 × 10⁹⁷(98-digit number)
36013982367298278672…85284291362860236801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.202 × 10⁹⁷(98-digit number)
72027964734596557345…70568582725720473601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.440 × 10⁹⁸(99-digit number)
14405592946919311469…41137165451440947201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
11
2^10 × origin + 1
2.881 × 10⁹⁸(99-digit number)
28811185893838622938…82274330902881894401
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:57,965,844 XPM·at block #6,840,189 · 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