Block #454,919

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/22/2014, 6:32:07 AM · Difficulty 10.3994 · 6,359,529 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
a50f1bf842ffc55f86b7b4632592b6ba9c3b2e8ea5b8d56c05e9f1dad166c38f

Height

#454,919

Difficulty

10.399435

Transactions

2

Size

3.79 KB

Version

2

Bits

0a66415e

Nonce

121,709

Timestamp

3/22/2014, 6:32:07 AM

Confirmations

6,359,529

Merkle Root

52eef5c40ccf99069e0b67ac01e1c6806b74d79a9ef46b178ae47ac375aec917
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.

5.285 × 10⁹⁷(98-digit number)
52854015093280673211…51291592017827584001
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
5.285 × 10⁹⁷(98-digit number)
52854015093280673211…51291592017827584001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
1.057 × 10⁹⁸(99-digit number)
10570803018656134642…02583184035655168001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
2.114 × 10⁹⁸(99-digit number)
21141606037312269284…05166368071310336001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
4.228 × 10⁹⁸(99-digit number)
42283212074624538568…10332736142620672001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
8.456 × 10⁹⁸(99-digit number)
84566424149249077137…20665472285241344001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
1.691 × 10⁹⁹(100-digit number)
16913284829849815427…41330944570482688001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
3.382 × 10⁹⁹(100-digit number)
33826569659699630855…82661889140965376001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
6.765 × 10⁹⁹(100-digit number)
67653139319399261710…65323778281930752001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
1.353 × 10¹⁰⁰(101-digit number)
13530627863879852342…30647556563861504001
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
2.706 × 10¹⁰⁰(101-digit number)
27061255727759704684…61295113127723008001
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:57,759,654 XPM·at block #6,814,447 · updates every 60s
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