Block #462,321

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/27/2014, 9:12:14 AM · Difficulty 10.4095 · 6,334,541 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
d0b69819bc8b1f1ba22ae3c5b12a474c6f682b951df51d33f09966bb2b6c26e3

Height

#462,321

Difficulty

10.409486

Transactions

9

Size

2.68 KB

Version

2

Bits

0a68d417

Nonce

49,728

Timestamp

3/27/2014, 9:12:14 AM

Confirmations

6,334,541

Merkle Root

b8dd26ce9d097acbd8420d03136ea07f1544a9bec9dc71635d5aaa4b6b70a184
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.

5.292 × 10⁹⁸(99-digit number)
52922436905997646034…29112440737659643301
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
5.292 × 10⁹⁸(99-digit number)
52922436905997646034…29112440737659643301
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.058 × 10⁹⁹(100-digit number)
10584487381199529206…58224881475319286601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.116 × 10⁹⁹(100-digit number)
21168974762399058413…16449762950638573201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.233 × 10⁹⁹(100-digit number)
42337949524798116827…32899525901277146401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.467 × 10⁹⁹(100-digit number)
84675899049596233655…65799051802554292801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.693 × 10¹⁰⁰(101-digit number)
16935179809919246731…31598103605108585601
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.387 × 10¹⁰⁰(101-digit number)
33870359619838493462…63196207210217171201
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.774 × 10¹⁰⁰(101-digit number)
67740719239676986924…26392414420434342401
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.354 × 10¹⁰¹(102-digit number)
13548143847935397384…52784828840868684801
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.709 × 10¹⁰¹(102-digit number)
27096287695870794769…05569657681737369601
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:57,618,910 XPM·at block #6,796,861 · updates every 60s
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