Block #450,613

2CCLength 10★★☆☆☆

Cunningham Chain of the Second Kind · Discovered 3/19/2014, 10:07:11 AM · Difficulty 10.3724 · 6,359,761 confirmations

2CC
Cunningham Chain of the Second Kind

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

Block Header
Block Hash
cb6e2df04a6715e06894f2bb6a57451ce3225c11bc1bbf77576a3e1ecdea1b14

Height

#450,613

Difficulty

10.372430

Transactions

2

Size

427 B

Version

2

Bits

0a5f579a

Nonce

58,192

Timestamp

3/19/2014, 10:07:11 AM

Confirmations

6,359,761

Merkle Root

775f7a728426027c7d8ef40ad010170eba5e8534a410de0d25e12f762989e1ba
Transactions (2)
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.

2.783 × 10⁹⁹(100-digit number)
27835775397988471428…05728192632617693121
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
2.783 × 10⁹⁹(100-digit number)
27835775397988471428…05728192632617693121
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
2
2^1 × origin + 1
5.567 × 10⁹⁹(100-digit number)
55671550795976942857…11456385265235386241
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
3
2^2 × origin + 1
1.113 × 10¹⁰⁰(101-digit number)
11134310159195388571…22912770530470772481
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
4
2^3 × origin + 1
2.226 × 10¹⁰⁰(101-digit number)
22268620318390777142…45825541060941544961
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
5
2^4 × origin + 1
4.453 × 10¹⁰⁰(101-digit number)
44537240636781554285…91651082121883089921
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
6
2^5 × origin + 1
8.907 × 10¹⁰⁰(101-digit number)
89074481273563108571…83302164243766179841
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
7
2^6 × origin + 1
1.781 × 10¹⁰¹(102-digit number)
17814896254712621714…66604328487532359681
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
8
2^7 × origin + 1
3.562 × 10¹⁰¹(102-digit number)
35629792509425243428…33208656975064719361
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
9
2^8 × origin + 1
7.125 × 10¹⁰¹(102-digit number)
71259585018850486857…66417313950129438721
Verify on FactorDB ↗Wolfram Alpha ↗
×2−1 →
10
2^9 × origin + 1
1.425 × 10¹⁰²(103-digit number)
14251917003770097371…32834627900258877441
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:57,727,068 XPM·at block #6,810,373 · updates every 60s
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