Block #444,258

1CCLength 10★★☆☆☆

Cunningham Chain of the First Kind · Discovered 3/15/2014, 3:55:55 AM · Difficulty 10.3406 · 6,354,314 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
b4285ff0ef5c83f5f5a929d50e8be5751958b6dca13eb2e39ecf35aca41f81ca

Height

#444,258

Difficulty

10.340602

Transactions

1

Size

936 B

Version

2

Bits

0a5731b5

Nonce

76,195

Timestamp

3/15/2014, 3:55:55 AM

Confirmations

6,354,314

Merkle Root

1852cd26c41be7069f874244a1fd6f053f7a6020443e87ada55e95f24b93592c
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.

2.960 × 10⁹⁶(97-digit number)
29602832123307296170…03070821868312965119
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
2.960 × 10⁹⁶(97-digit number)
29602832123307296170…03070821868312965119
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
5.920 × 10⁹⁶(97-digit number)
59205664246614592341…06141643736625930239
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
1.184 × 10⁹⁷(98-digit number)
11841132849322918468…12283287473251860479
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
2.368 × 10⁹⁷(98-digit number)
23682265698645836936…24566574946503720959
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
4.736 × 10⁹⁷(98-digit number)
47364531397291673873…49133149893007441919
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
9.472 × 10⁹⁷(98-digit number)
94729062794583347746…98266299786014883839
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.894 × 10⁹⁸(99-digit number)
18945812558916669549…96532599572029767679
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
3.789 × 10⁹⁸(99-digit number)
37891625117833339098…93065199144059535359
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
7.578 × 10⁹⁸(99-digit number)
75783250235666678196…86130398288119070719
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
1.515 × 10⁹⁹(100-digit number)
15156650047133335639…72260796576238141439
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:57,632,594 XPM·at block #6,798,571 · updates every 60s
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