Block #184,098

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 9/28/2013, 10:55:01 AM · Difficulty 9.8591 · 6,618,414 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
32ec501898751408790310f05462b53a13bb51d538c6f860da2c1e3f9519e067

Height

#184,098

Difficulty

9.859130

Transactions

8

Size

10.99 KB

Version

2

Bits

09dbeff4

Nonce

33,468

Timestamp

9/28/2013, 10:55:01 AM

Confirmations

6,618,414

Merkle Root

a518ed2655edebc00a1511fa1a145c86521d0e3115fa58a8e757749f5b0c8b18
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.

3.088 × 10⁸⁸(89-digit number)
30883013564738279322…74347414102641298961
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
3.088 × 10⁸⁸(89-digit number)
30883013564738279322…74347414102641298961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.176 × 10⁸⁸(89-digit number)
61766027129476558644…48694828205282597921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.235 × 10⁸⁹(90-digit number)
12353205425895311728…97389656410565195841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.470 × 10⁸⁹(90-digit number)
24706410851790623457…94779312821130391681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.941 × 10⁸⁹(90-digit number)
49412821703581246915…89558625642260783361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.882 × 10⁸⁹(90-digit number)
98825643407162493831…79117251284521566721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.976 × 10⁹⁰(91-digit number)
19765128681432498766…58234502569043133441
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.953 × 10⁹⁰(91-digit number)
39530257362864997532…16469005138086266881
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.906 × 10⁹⁰(91-digit number)
79060514725729995065…32938010276172533761
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 9 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
CommonChain length 9

Found in most blocks. The baseline for Primecoin's proof-of-work.

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:57,664,104 XPM·at block #6,802,511 · 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.