Block #489,356

1CCLength 11★★★☆☆

Cunningham Chain of the First Kind · Discovered 4/13/2014, 5:59:42 AM · Difficulty 10.6649 · 6,323,683 confirmations

1CC
Cunningham Chain of the First Kind

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

Block Header
Block Hash
eb8d75dbc1ef621a4849bd5fe359d1bb4964e58c38bea8689ce50c12e220575a

Height

#489,356

Difficulty

10.664883

Transactions

5

Size

1.08 KB

Version

2

Bits

0aaa35c0

Nonce

8,237,124

Timestamp

4/13/2014, 5:59:42 AM

Confirmations

6,323,683

Merkle Root

4818039f5125b9016fc0a3d932f1abd5f9d9452823306851b67f93ecd20a77b9
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.

1.917 × 10⁹⁸(99-digit number)
19171627015336906856…55243485556988048799
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
1.917 × 10⁹⁸(99-digit number)
19171627015336906856…55243485556988048799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
2
2^1 × origin − 1
3.834 × 10⁹⁸(99-digit number)
38343254030673813712…10486971113976097599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
3
2^2 × origin − 1
7.668 × 10⁹⁸(99-digit number)
76686508061347627424…20973942227952195199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
4
2^3 × origin − 1
1.533 × 10⁹⁹(100-digit number)
15337301612269525484…41947884455904390399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
5
2^4 × origin − 1
3.067 × 10⁹⁹(100-digit number)
30674603224539050969…83895768911808780799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
6
2^5 × origin − 1
6.134 × 10⁹⁹(100-digit number)
61349206449078101939…67791537823617561599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
7
2^6 × origin − 1
1.226 × 10¹⁰⁰(101-digit number)
12269841289815620387…35583075647235123199
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
8
2^7 × origin − 1
2.453 × 10¹⁰⁰(101-digit number)
24539682579631240775…71166151294470246399
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
9
2^8 × origin − 1
4.907 × 10¹⁰⁰(101-digit number)
49079365159262481551…42332302588940492799
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
10
2^9 × origin − 1
9.815 × 10¹⁰⁰(101-digit number)
98158730318524963102…84664605177880985599
Verify on FactorDB ↗Wolfram Alpha ↗
×2+1 →
11
2^10 × origin − 1
1.963 × 10¹⁰¹(102-digit number)
19631746063704992620…69329210355761971199
Verify on FactorDB ↗Wolfram Alpha ↗

What this block proved

The miner who found this block proved the existence of 11 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
RareChain length 11

Approximately 1 in 1,000 blocks. Noteworthy discoveries.

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:57,748,356 XPM·at block #6,813,038 · updates every 60s
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