Block #94,182

2CCLength 9★☆☆☆☆

Cunningham Chain of the Second Kind · Discovered 8/2/2013, 10:20:35 PM · Difficulty 9.2018 · 6,700,364 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
623fb01e1ea991e85d3e64fa876281576f81b59e627b037cb132e136abf68d08

Height

#94,182

Difficulty

9.201785

Transactions

5

Size

1.66 KB

Version

2

Bits

0933a82e

Nonce

95,469

Timestamp

8/2/2013, 10:20:35 PM

Confirmations

6,700,364

Merkle Root

fe84f2223e1a66d068891bd6822547acbfad36a879be2e8ecb2fb493759cf824
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.

3.085 × 10¹⁰⁸(109-digit number)
30853625429525287122…52841897087031509811
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
3.085 × 10¹⁰⁸(109-digit number)
30853625429525287122…52841897087031509811
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
6.170 × 10¹⁰⁸(109-digit number)
61707250859050574244…05683794174063019621
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.234 × 10¹⁰⁹(110-digit number)
12341450171810114848…11367588348126039241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.468 × 10¹⁰⁹(110-digit number)
24682900343620229697…22735176696252078481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.936 × 10¹⁰⁹(110-digit number)
49365800687240459395…45470353392504156961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
9.873 × 10¹⁰⁹(110-digit number)
98731601374480918790…90940706785008313921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.974 × 10¹¹⁰(111-digit number)
19746320274896183758…81881413570016627841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.949 × 10¹¹⁰(111-digit number)
39492640549792367516…63762827140033255681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.898 × 10¹¹⁰(111-digit number)
78985281099584735032…27525654280066511361
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:57,600,408 XPM·at block #6,794,545 · updates every 60s
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