Block #379,289

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 1/28/2014, 10:52:44 AM · Difficulty 10.4162 · 6,447,219 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
3cb7a7aa12f196f7c497265fd0e36a25c4e63540770e0c8f18798023b37f787b

Height

#379,289

Difficulty

10.416242

Transactions

4

Size

1.59 KB

Version

2

Bits

0a6a8ece

Nonce

16,426

Timestamp

1/28/2014, 10:52:44 AM

Confirmations

6,447,219

Merkle Root

91dd9bca38c8f4aef00750f4a216af3621036f16bf82acbed3c2d5510e45c024
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.

2.468 × 10⁹⁹(100-digit number)
24684671711784965742…83860169757801973759
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
2.468 × 10⁹⁹(100-digit number)
24684671711784965742…83860169757801973759
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
4.936 × 10⁹⁹(100-digit number)
49369343423569931484…67720339515603947519
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
9.873 × 10⁹⁹(100-digit number)
98738686847139862969…35440679031207895039
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.974 × 10¹⁰⁰(101-digit number)
19747737369427972593…70881358062415790079
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.949 × 10¹⁰⁰(101-digit number)
39495474738855945187…41762716124831580159
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
7.899 × 10¹⁰⁰(101-digit number)
78990949477711890375…83525432249663160319
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.579 × 10¹⁰¹(102-digit number)
15798189895542378075…67050864499326320639
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.159 × 10¹⁰¹(102-digit number)
31596379791084756150…34101728998652641279
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
6.319 × 10¹⁰¹(102-digit number)
63192759582169512300…68203457997305282559
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.263 × 10¹⁰²(103-digit number)
12638551916433902460…36406915994610565119
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 First 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 1CC formula:

1CC: p₁ (first prime), p₂ = 2p₁ + 1, p₃ = 2p₂ + 1, …
Circulating Supply:57,856,207 XPM·at block #6,826,507 · updates every 60s
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